diff --git a/MEMORY.md b/MEMORY.md
index 93778b6..0380db0 100644
--- a/MEMORY.md
+++ b/MEMORY.md
@@ -34,6 +34,7 @@ Architecture: Modular Hexagonal/DDD.
 * Security: Remediated Medium severity security findings (secured Swagger UI in production, sanitized global exception handler, downgraded JWT logging, and unified login error messages).
 * System: Configured Docker containers (backend, frontend, db) to automatically restart after server reboot using 'restart: unless-stopped' policy in docker-compose.yml.
 * Backend: Implemented dynamic Image Consensus Threshold feature using an asynchronous `ThresholdEventListener` that intercepts `ClassificationSubmittedEvent`. It evaluates the weighted credibility of classifications and automatically excludes images from distribution (via `ConsensusResult` tracking) once the dynamic researcher-defined threshold is met.
+* Backend/Frontend: Optimized the CSV Export System (Issue #257). Implemented a non-blocking, background-execution export flow in the frontend using a global Zustand store and an animated `GlobalDownloadToast`. Cleaned up the backend CSV generation (`ExportService`) to significantly reduce file size and improve traceability by removing the raw base64 image strings and replacing them with explicit local and external IDs (`swipelab_image_id`, `stardbi_experiment_id`, `stardbi_image_id`, `stardbi_crop_id`).
 ## Current Focus (Active GitHub Issues)
 * Issue #201: Refactor Backend roles to include Researchers and Super Admin.
 * Issue #226: [Frontend] fix recipients list not deleting users.
diff --git a/backend/src/docs/analytics.md b/backend/src/docs/analytics.md
index d14417e..ff56a0c 100644
--- a/backend/src/docs/analytics.md
+++ b/backend/src/docs/analytics.md
@@ -28,3 +28,8 @@ A heavily cached, expensive query that provides a comprehensive platform snapsho
 - **Time Windows**: Shows activity (classifications, unique users, tasks) for "Today", "This Week", and "This Month".
 - **Confidence Trend**: Tracks average user credibility scores over a 30-day window.
 - **Label Distribution**: Shows the split of YES / NO / UNSURE labels over time.
+
+## 6. Data Export (CSV & JSON)
+Researchers and SuperAdmins can export classification datasets in CSV and JSON formats. These exports are highly optimized for both performance and readability:
+- **Traceability**: All exported rows include strict cross-system mapping identifiers (`swipelab_image_id`, `stardbi_experiment_id`, `stardbi_image_id`, and `stardbi_crop_id`).
+- **Optimization**: Raw Base64 image strings are completely omitted from the generated files, vastly reducing network latency and file sizes (e.g., bringing a row payload down from ~100+ KB to ~150 bytes).
diff --git a/backend/src/docs/api/analytics-api.md b/backend/src/docs/api/analytics-api.md
index b2e9234..ada0378 100644
--- a/backend/src/docs/api/analytics-api.md
+++ b/backend/src/docs/api/analytics-api.md
@@ -25,3 +25,12 @@ Base path: `/api/v1/admin/export`
 | `GET` | `/tasks/{taskId}/summary` | Export task summary |
 | `GET` | `/tasks/{taskId}/csv` | Export task data as CSV |
 | `GET` | `/tasks/{taskId}/json` | Export task data as JSON |
+
+### Export Data Schema
+
+The CSV and JSON exports are optimized for performance and file size by omitting raw Base64 image strings. They contain the following cross-system traceability identifiers to reliably map classifications back to their source:
+
+- `swipelab_image_id`: Internal primary key of the image in the SwipeLab database.
+- `stardbi_experiment_id`: External ID mapping to the StarDBi experiment.
+- `stardbi_image_id`: External ID mapping to the StarDBi parent image.
+- `stardbi_crop_id`: External ID mapping to the StarDBi bounding box/crop.
diff --git a/backend/src/docs/metrics.md b/backend/src/docs/metrics.md
new file mode 100644
index 0000000..aa29462
--- /dev/null
+++ b/backend/src/docs/metrics.md
@@ -0,0 +1,58 @@
+# SwipeLab Analytics Metrics Documentation
+
+This document explains the mathematical formulas and backend implementation logic behind the analytics data generated by `AnalyticsService.java` for the Researcher Dashboard.
+
+## 1. User Accuracy (Gold Accuracy)
+
+### What it is
+The accuracy score tracks how effectively a user is identifying correct classifications, serving as a primary indicator of data labeling quality. 
+
+### How it is calculated
+Since normal images in the dataset do not have a known "correct" answer, a user's accuracy is **only evaluated based on their performance against Gold Images** (test images with pre-verified answers).
+
+* **Formula**: `Correct Gold Classifications / Total Gold Classifications`
+* **Backend Source**: `ClassificationFactRepository.java`
+* **Implementation Note**: The system specifically filters for `c.isCorrect IS NOT NULL` to determine `Total Gold Classifications`. Normal classifications (where `isCorrect` is null) are completely excluded from the denominator to prevent artificially deflating the user's accuracy score to ~0.0%.
+
+## 2. Participation Metrics
+
+### What it is
+These metrics measure engagement volume and speed for a specific classification task.
+
+### How it is calculated
+* **Active Users**: The count of distinct, unique `userId` values associated with the `ClassificationFact` entries for the task.
+* **Total Classifications**: The absolute total count of all `ClassificationFact` rows (swipes) executed against this task.
+* **Average Classifications per User**: `Total Classifications / Active Users`.
+* **Median Response Time**: 
+    * The backend retrieves the `responseTimeMs` (the time taken between an image appearing on screen and the user swiping) for every single classification fact.
+    * Null values are filtered out.
+    * The list is sorted, and the median value (middle element, or average of two middle elements) is returned.
+
+## 3. Data Quality Metrics
+
+### What it is
+These metrics evaluate the overall trustworthiness of the labels being generated for a task based on user credibility.
+
+### How it is calculated
+* **Average Credibility**: 
+    * Every time a user makes a classification, their *current credibility score at that exact moment* is snapshotted into `credibilityAtTime`.
+    * The backend calculates the global average of `credibilityAtTime` across all facts in the task.
+* **Low Quality Users**:
+    * The system groups all classification facts by `userId` and calculates the average credibility for each specific user within this task.
+    * A user is flagged as a "Low Quality User" if their average credibility score drops below the threshold of **50.0/100**.
+    * The final metric returns the absolute count of users who fall below this threshold.
+
+## 4. Consensus Metrics
+
+### What it is
+Consensus evaluates how strongly the crowd agrees on the labels for the images in the task.
+
+### How it is calculated
+* **Overall Average Consensus**:
+    * The backend groups all `ClassificationFact` rows by `imageId`.
+    * For each image, it extracts the `consensusScore` (taking the maximum/latest recorded score for that image).
+    * It then averages these scores across all classified images in the task.
+    * The result is represented as a percentage (0-100%).
+* **Low Consensus Images**:
+    * While calculating the above, the system checks each image's `consensusScore` against a strict threshold (currently `0.8` or 80%).
+    * Any image with a score below this threshold increments the "Low Consensus Images" counter. This highlights complex, ambiguous, or highly-debated images that may require researcher intervention.
diff --git a/backend/src/main/java/com/swipelab/analytics/application/AnalyticsEventListener.java b/backend/src/main/java/com/swipelab/analytics/application/AnalyticsEventListener.java
index 9f44889..9005078 100644
--- a/backend/src/main/java/com/swipelab/analytics/application/AnalyticsEventListener.java
+++ b/backend/src/main/java/com/swipelab/analytics/application/AnalyticsEventListener.java
@@ -76,10 +76,14 @@ private void updateUserDailyStats(ClassificationSubmittedEvent event, LocalDate
                         .build());
 
         stats.setTotal(stats.getTotal() + 1);
-        if (event.isCorrect()) {
+        if (event.isGoldStandard() && event.isCorrect()) {
             stats.setCorrect(stats.getCorrect() + 1);
         }
-        stats.setAccuracy(stats.getTotal() > 0 ? (double) stats.getCorrect() / stats.getTotal() : 0.0);
+        
+        // Note: For true daily accuracy we need a count of gold classifications for the day.
+        // For now, we will leave the denormalized accuracy at 0.0 or calculate a rough estimate,
+        // since the UI fetches live accuracy from the facts table directly.
+        stats.setAccuracy(0.0);
 
         userDailyStatsRepository.save(stats);
     }
diff --git a/backend/src/main/java/com/swipelab/analytics/application/AnalyticsService.java b/backend/src/main/java/com/swipelab/analytics/application/AnalyticsService.java
index 5433405..77ac289 100644
--- a/backend/src/main/java/com/swipelab/analytics/application/AnalyticsService.java
+++ b/backend/src/main/java/com/swipelab/analytics/application/AnalyticsService.java
@@ -5,6 +5,7 @@
 import com.swipelab.analytics.infrastructure.*;
 import com.swipelab.classification.domain.core.Classification.UserResponse;
 import com.swipelab.classification.infrastructure.ClassificationRepository;
+import com.swipelab.classification.infrastructure.ConsensusResultRepository;
 import com.swipelab.classification.infrastructure.ImageRepository;
 import com.swipelab.config.CacheConfig;
 import com.swipelab.analytics.dto.DashboardStatsResponse;
@@ -43,6 +44,7 @@ public class AnalyticsService {
     private final UserRepository userRepository;
     private final TaskRepository taskRepository;
     private final ImageRepository imageRepository;
+    private final ConsensusResultRepository consensusResultRepository;
 
     // ─── User-scoped endpoints ────────────────────────────────────────────────
 
@@ -62,7 +64,8 @@ public UserProgressResponse getUserProgress(String userId) {
             }
         }
 
-        double accuracy = total > 0 ? (double) correct / total : 0.0;
+        Double calculatedAccuracy = classificationFactRepository.getUserAccuracy(userId);
+        double accuracy = calculatedAccuracy != null ? calculatedAccuracy : 0.0;
 
         return UserProgressResponse.builder()
                 .completed((int) total)
@@ -83,7 +86,9 @@ public UserStatisticsResponse getUserStatistics(String userId) {
                 correct = row[1] != null ? ((Number) row[1]).longValue() : 0;
             }
         }
-        double accuracy = total > 0 ? (double) correct / total : 0.0;
+        
+        Double calculatedAccuracy = classificationFactRepository.getUserAccuracy(userId);
+        double accuracy = calculatedAccuracy != null ? calculatedAccuracy : 0.0;
 
         UserRanking ranking = userRankingRepository.findByUserIdAndPeriod(userId, "ALL_TIME")
                 .orElse(UserRanking.builder().rank(0).percentile(0).build());
@@ -194,7 +199,8 @@ public TimeSeriesResponse getTimeSeries(String userId, String metric, String per
 
     @Transactional(readOnly = true)
     public TaskAnalyticsResponse getTaskAnalytics(Long taskId) {
-        Long completedImages = classificationFactRepository.countCompletedImages(taskId);
+        Long imagesClassified = classificationFactRepository.countDistinctImagesByTaskId(taskId);
+        Long completedImages = consensusResultRepository.countCompletedImagesByTaskId(taskId);
         List<ClassificationFact> facts = classificationFactRepository.findByTaskId(taskId);
         int totalClassifications = facts.size();
 
@@ -204,7 +210,7 @@ public TaskAnalyticsResponse getTaskAnalytics(Long taskId) {
                 : 0.0;
 
         TaskAnalyticsResponse.Progress progress = TaskAnalyticsResponse.Progress.builder()
-                .imagesClassified(completedImages.intValue())
+                .imagesClassified(imagesClassified.intValue())
                 .totalImages(totalImages)
                 .completedImages(completedImages.intValue())
                 .percentComplete(percentComplete)
@@ -225,15 +231,88 @@ public TaskAnalyticsResponse getTaskAnalytics(Long taskId) {
                         .build())
                 .collect(Collectors.toList());
 
+        // ─── Participation ──────────────────
+        long activeUsers = facts.stream().map(ClassificationFact::getUserId).distinct().count();
+        int avgClassifications = activeUsers > 0 ? (int) (totalClassifications / activeUsers) : 0;
+        
+        List<Long> responseTimes = facts.stream()
+                .map(ClassificationFact::getResponseTimeMs)
+                .filter(java.util.Objects::nonNull)
+                .sorted()
+                .collect(Collectors.toList());
+        long medianResponseTime = 0L;
+        if (!responseTimes.isEmpty()) {
+            int mid = responseTimes.size() / 2;
+            medianResponseTime = responseTimes.size() % 2 == 1 
+                ? responseTimes.get(mid) 
+                : (responseTimes.get(mid - 1) + responseTimes.get(mid)) / 2;
+        }
+
+        TaskAnalyticsResponse.Participation participation = TaskAnalyticsResponse.Participation.builder()
+                .activeUsers((int) activeUsers)
+                .totalClassifications(totalClassifications)
+                .averageClassificationsPerUser(avgClassifications)
+                .medianResponseTimeMs(medianResponseTime)
+                .build();
+
+        // ─── Quality ────────────────────────
+        double sumCredibility = 0;
+        int credibilityCount = 0;
+        Map<String, List<Double>> userCredibility = new HashMap<>();
+        for (ClassificationFact f : facts) {
+            if (f.getCredibilityAtTime() != null) {
+                sumCredibility += f.getCredibilityAtTime();
+                credibilityCount++;
+                userCredibility.computeIfAbsent(f.getUserId(), k -> new ArrayList<>()).add(f.getCredibilityAtTime());
+            }
+        }
+        double avgCredibility = credibilityCount > 0 ? sumCredibility / credibilityCount : 0.0;
+        
+        int lowQualityCount = 0;
+        for (List<Double> creds : userCredibility.values()) {
+            double uAvg = creds.stream().mapToDouble(Double::doubleValue).average().orElse(100.0);
+            if (uAvg < 50.0) {
+                lowQualityCount++;
+            }
+        }
+
+        TaskAnalyticsResponse.Quality quality = TaskAnalyticsResponse.Quality.builder()
+                .averageCredibility(avgCredibility)
+                .lowQualityUsers(lowQualityCount)
+                .build();
+
+        // ─── Consensus ──────────────────────
+        Map<Long, Double> imageConsensus = new HashMap<>();
+        for (ClassificationFact f : facts) {
+            if (f.getConsensusScore() != null) {
+                imageConsensus.merge(f.getImageId(), f.getConsensusScore(), Math::max);
+            }
+        }
+        double sumConsensus = 0;
+        int lowConsensusImages = 0;
+        for (Double score : imageConsensus.values()) {
+            sumConsensus += score;
+            if (score < 0.8) {
+                lowConsensusImages++;
+            }
+        }
+        double avgConsensus = imageConsensus.isEmpty() ? 0.0 : (sumConsensus / imageConsensus.size()) * 100.0;
+
+        TaskAnalyticsResponse.Consensus consensus = TaskAnalyticsResponse.Consensus.builder()
+                .overallAverage(avgConsensus)
+                .lowConsensusImages(lowConsensusImages)
+                .threshold(0.8)
+                .build();
+
         return TaskAnalyticsResponse.builder()
                 .taskId(taskId)
                 .status("ACTIVE")
                 .progress(progress)
                 .speciesAnalytics(saList)
                 .generatedAt(java.time.LocalDateTime.now().toString())
-                .consensus(TaskAnalyticsResponse.Consensus.builder().build())
-                .participation(TaskAnalyticsResponse.Participation.builder().build())
-                .quality(TaskAnalyticsResponse.Quality.builder().build())
+                .consensus(consensus)
+                .participation(participation)
+                .quality(quality)
                 .timeSeries(List.of())
                 .build();
     }
@@ -355,14 +434,15 @@ private UserPerformanceResponse mapToUserPerformanceResponse(Object[] row) {
         String username = (String) row[0];
         int total = row[1] != null ? ((Number) row[1]).intValue() : 0;
         int correct = row[2] != null ? ((Number) row[2]).intValue() : 0;
-        double avgCredibility = row[3] != null ? ((Number) row[3]).doubleValue() : 0.0;
-        double accuracy = total > 0 ? (double) correct / total : 0.0;
+        int goldTotal = row[3] != null ? ((Number) row[3]).intValue() : 0;
+        double avgCredibility = row[4] != null ? ((Number) row[4]).doubleValue() : 0.0;
+        double accuracy = goldTotal > 0 ? (double) correct / goldTotal : 0.0;
 
         return UserPerformanceResponse.builder()
                 .username(username)
                 .displayName(username)
                 .totalClassifications(total)
-                .goldImageClassifications(0)
+                .goldImageClassifications(goldTotal)
                 .correctGoldClassifications(correct)
                 .goldAccuracy(accuracy)
                 .credibilityScore(avgCredibility)
diff --git a/backend/src/main/java/com/swipelab/analytics/application/ExportService.java b/backend/src/main/java/com/swipelab/analytics/application/ExportService.java
index 9a29776..d8de6c9 100644
--- a/backend/src/main/java/com/swipelab/analytics/application/ExportService.java
+++ b/backend/src/main/java/com/swipelab/analytics/application/ExportService.java
@@ -43,10 +43,10 @@ public class ExportService {
     private static final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ISO_LOCAL_DATE_TIME;
 
     // Legacy header kept for backward-compatible single-task endpoints
-    private static final String LEGACY_CSV_HEADER = "parent_image_id,crop_id,image_data,username,user_response,classified_at,is_gold_standard";
+    private static final String LEGACY_CSV_HEADER = "swipelab_image_id,stardbi_experiment_id,stardbi_image_id,stardbi_crop_id,username,user_response,classified_at,is_gold_standard";
 
     private static final String MULTI_EXPORT_CSV_HEADER =
-            "classification_id,task_id,task_name,parent_image_id,crop_id,image_src_path,username,user_role,query_species,user_response,credibility_score,is_gold_standard,classified_at";
+            "classification_id,task_id,task_name,swipelab_image_id,stardbi_experiment_id,stardbi_image_id,stardbi_crop_id,username,user_role,query_species,user_response,credibility_score,is_gold_standard,classified_at";
 
     // ─── Multi-task export (Issue #257) ───────────────────────────────────────
 
@@ -101,13 +101,14 @@ public void exportMultiTaskClassificationsAsCsv(List<Long> taskIds, String usern
                 Image image = c.getImage();
                 boolean isGold = goldImageRepository.existsByImageId(image.getId());
 
-                String row = String.format("%d,%d,\"%s\",%s,%s,\"%s\",\"%s\",\"%s\",\"%s\",\"%s\",%s,%b,\"%s\"",
+                String row = String.format("%d,%d,\"%s\",%d,%s,%s,%s,\"%s\",\"%s\",\"%s\",\"%s\",%s,%b,\"%s\"",
                         c.getId(),
                         c.getTaskId(),
                         escapeCsv(taskNameMap.getOrDefault(c.getTaskId(), "")),
+                        image.getId(),
+                        image.getExperimentId() != null ? image.getExperimentId().toString() : "",
                         image.getParentImageId() != null ? image.getParentImageId().toString() : "",
                         image.getExternalBoxId() != null ? image.getExternalBoxId().toString() : "",
-                        escapeCsv(image.getImageData()),
                         escapeCsv(c.getUsername()),
                         escapeCsv(c.getUserRole() != null ? c.getUserRole() : ""),
                         escapeCsv(c.getQuerySpecies() != null ? c.getQuerySpecies() : ""),
@@ -188,7 +189,7 @@ public Map<String, Object> getExportSummary(Long taskId) {
         summary.put("taskId", taskId);
         summary.put("totalImages", totalImages);
         summary.put("totalClassifications", totalClassifications);
-        summary.put("estimatedCsvSizeKb", totalClassifications * 100 / 1024); // ~100 bytes per row
+        summary.put("estimatedCsvSizeKb", totalClassifications * 150 / 1024); // ~150 bytes per row
 
         return summary;
     }
@@ -197,10 +198,11 @@ public Map<String, Object> getExportSummary(Long taskId) {
 
     private String formatLegacyCsvRow(Classification classification, boolean isGoldStandard) {
         Image image = classification.getImage();
-        return String.format("%s,%s,\"%s\",\"%s\",\"%s\",\"%s\",%b",
+        return String.format("%d,%s,%s,%s,\"%s\",\"%s\",\"%s\",%b",
+                image.getId(),
+                image.getExperimentId() != null ? image.getExperimentId().toString() : "",
                 image.getParentImageId() != null ? image.getParentImageId().toString() : "",
                 image.getExternalBoxId() != null ? image.getExternalBoxId().toString() : "",
-                escapeCsv(image.getImageData()),
                 escapeCsv(classification.getUsername()),
                 escapeCsv(classification.getUserResponse().name()),
                 classification.getCreatedAt() != null ? classification.getCreatedAt().format(DATE_FORMATTER) : "",
@@ -210,9 +212,10 @@ private String formatLegacyCsvRow(Classification classification, boolean isGoldS
     private Map<String, Object> formatJsonObject(Classification classification, boolean isGoldStandard) {
         Image image = classification.getImage();
         Map<String, Object> obj = new HashMap<>();
-        obj.put("imageId", image.getParentImageId());
-        obj.put("cropId", image.getExternalBoxId());
-        obj.put("imageData", image.getImageData());
+        obj.put("swipelabImageId", image.getId());
+        obj.put("stardbiExperimentId", image.getExperimentId());
+        obj.put("stardbiImageId", image.getParentImageId());
+        obj.put("stardbiCropId", image.getExternalBoxId());
         obj.put("username", classification.getUsername());
         obj.put("userResponse", classification.getUserResponse().name());
         obj.put("classifiedAt",
diff --git a/backend/src/main/java/com/swipelab/analytics/infrastructure/ClassificationFactRepository.java b/backend/src/main/java/com/swipelab/analytics/infrastructure/ClassificationFactRepository.java
index 93bbc29..8b02ebe 100644
--- a/backend/src/main/java/com/swipelab/analytics/infrastructure/ClassificationFactRepository.java
+++ b/backend/src/main/java/com/swipelab/analytics/infrastructure/ClassificationFactRepository.java
@@ -14,20 +14,20 @@ public interface ClassificationFactRepository extends JpaRepository<Classificati
 
     // ─── Existing user-scoped queries ────────────────────────────────────────
 
-    @Query("SELECT AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) FROM ClassificationFact c WHERE c.userId = :userId")
+    @Query("SELECT AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) FROM ClassificationFact c WHERE c.userId = :userId AND c.isCorrect IS NOT NULL")
     Double getUserAccuracy(@Param("userId") String userId);
 
-    @Query("SELECT AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) FROM ClassificationFact c WHERE c.isExpert = true")
+    @Query("SELECT AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) FROM ClassificationFact c WHERE c.isExpert = true AND c.isCorrect IS NOT NULL")
     Double getGlobalExpertAccuracy();
 
-    @Query("SELECT AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) FROM ClassificationFact c")
+    @Query("SELECT AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) FROM ClassificationFact c WHERE c.isCorrect IS NOT NULL")
     Double getGlobalAverageAccuracy();
 
     @Query("SELECT COUNT(DISTINCT c.imageId) FROM ClassificationFact c WHERE c.taskId = :taskId")
-    Long countCompletedImages(@Param("taskId") Long taskId);
+    Long countDistinctImagesByTaskId(@Param("taskId") Long taskId);
 
     @Query("SELECT c.species, COUNT(c), AVG(CASE WHEN c.isCorrect = true THEN 1.0 ELSE 0.0 END) " +
-            "FROM ClassificationFact c WHERE c.userId = :userId GROUP BY c.species")
+            "FROM ClassificationFact c WHERE c.userId = :userId AND c.isCorrect IS NOT NULL GROUP BY c.species")
     List<Object[]> getSpeciesBreakdown(@Param("userId") String userId);
 
     List<ClassificationFact> findByTaskId(Long taskId);
@@ -76,6 +76,7 @@ public interface ClassificationFactRepository extends JpaRepository<Classificati
      */
     @Query("SELECT c.userId, COUNT(c), " +
             "SUM(CASE WHEN c.isCorrect = true THEN 1 ELSE 0 END), " +
+            "SUM(CASE WHEN c.isCorrect IS NOT NULL THEN 1 ELSE 0 END), " +
             "AVG(c.credibilityAtTime) " +
             "FROM ClassificationFact c " +
             "WHERE (:taskId IS NULL OR c.taskId = :taskId) " +
@@ -87,6 +88,7 @@ public interface ClassificationFactRepository extends JpaRepository<Classificati
      */
     @Query("SELECT c.userId, COUNT(c) as total, " +
             "SUM(CASE WHEN c.isCorrect = true THEN 1 ELSE 0 END), " +
+            "SUM(CASE WHEN c.isCorrect IS NOT NULL THEN 1 ELSE 0 END), " +
             "AVG(c.credibilityAtTime) " +
             "FROM ClassificationFact c " +
             "GROUP BY c.userId ORDER BY total DESC")
diff --git a/backend/src/main/java/com/swipelab/classification/infrastructure/ConsensusResultRepository.java b/backend/src/main/java/com/swipelab/classification/infrastructure/ConsensusResultRepository.java
index da79dc1..22d4a74 100644
--- a/backend/src/main/java/com/swipelab/classification/infrastructure/ConsensusResultRepository.java
+++ b/backend/src/main/java/com/swipelab/classification/infrastructure/ConsensusResultRepository.java
@@ -16,4 +16,7 @@ public interface ConsensusResultRepository extends JpaRepository<ConsensusResult
     List<String> findCompletedSpeciesByImageId(@Param("imageId") Long imageId);
 
     Optional<ConsensusResult> findByImageIdAndSpecies(Long imageId, String species);
+
+    @Query("SELECT COUNT(DISTINCT c.imageId) FROM ConsensusResult c WHERE c.taskId = :taskId")
+    Long countCompletedImagesByTaskId(@Param("taskId") Long taskId);
 }
diff --git a/backend/src/main/java/com/swipelab/config/CacheControlInterceptor.java b/backend/src/main/java/com/swipelab/config/CacheControlInterceptor.java
index 8ac42cd..aec7278 100644
--- a/backend/src/main/java/com/swipelab/config/CacheControlInterceptor.java
+++ b/backend/src/main/java/com/swipelab/config/CacheControlInterceptor.java
@@ -95,20 +95,17 @@ public boolean preHandle(HttpServletRequest request,
             return true;
         }
 
-        // ── Task details (stable once created) ────────────────────────────────
-        if (path.matches(".*/tasks/my-tasks/[^/]+")
-                || path.matches(".*/tasks/dashboard/[^/]+")) {
-            response.setHeader(CACHE_CONTROL, PRIVATE_120S);
-            return true;
-        }
-
-        // ── Personalised task lists (change on every assignment) ──────────────
-        // These are per-user and mutate the moment the user self-assigns a task.
-        // Any HTTP cache here would race with the frontend refetch and serve
-        // stale data, so they must always go to the network.
+        // ── Task lists & details (always revalidate with backend) ────────────
+        // These are volatile and mutate the moment the user self-assigns a task
+        // or a researcher pauses/archives a task. We use NO_CACHE_PRIVATE so
+        // the client caches them but ALWAYS revalidates via ETags, preventing
+        // stale UI bugs while saving bandwidth when nothing has changed.
         if (path.equals("/api/v1/tasks/my-tasks")
-                || path.equals("/api/v1/tasks/available-tasks")) {
-            response.setHeader(CACHE_CONTROL, NO_STORE);
+                || path.equals("/api/v1/tasks/available-tasks")
+                || path.equals("/api/v1/tasks/dashboard")
+                || path.matches(".*/tasks/my-tasks/[^/]+")
+                || path.matches(".*/tasks/dashboard/[^/]+")) {
+            response.setHeader(CACHE_CONTROL, NO_CACHE_PRIVATE);
             return true;
         }
 
diff --git a/backend/src/main/java/com/swipelab/exception/GlobalExceptionHandler.java b/backend/src/main/java/com/swipelab/exception/GlobalExceptionHandler.java
index fc7da42..6c36c2c 100644
--- a/backend/src/main/java/com/swipelab/exception/GlobalExceptionHandler.java
+++ b/backend/src/main/java/com/swipelab/exception/GlobalExceptionHandler.java
@@ -134,7 +134,7 @@ public ResponseEntity<ErrorResponse> handleDuplicateResourceException(
         }
 
         @ExceptionHandler({ EmailVerificationException.class, PasswordResetException.class,
-                        IllegalArgumentException.class })
+                        IllegalArgumentException.class, IllegalStateException.class })
         public ResponseEntity<ErrorResponse> handleBadRequestExceptions(
                         RuntimeException ex, HttpServletRequest request) {
 
diff --git a/backend/src/main/java/com/swipelab/gamification/api/GamificationController.java b/backend/src/main/java/com/swipelab/gamification/api/GamificationController.java
index 229879e..9a3d6a0 100644
--- a/backend/src/main/java/com/swipelab/gamification/api/GamificationController.java
+++ b/backend/src/main/java/com/swipelab/gamification/api/GamificationController.java
@@ -36,6 +36,7 @@ public ResponseEntity<GamificationUserInfoResponse> getUserInfo(
                 .score(gamification.getScore())
                 .badge(gamification.getBadge())
                 .currentStreak(gamification.getCurrentStreak())
+                .longestStreak(gamification.getLongestStreak())
                 .build());
     }
 
diff --git a/backend/src/main/java/com/swipelab/gamification/dto/GamificationUserInfoResponse.java b/backend/src/main/java/com/swipelab/gamification/dto/GamificationUserInfoResponse.java
index f8a40d9..c4866f0 100644
--- a/backend/src/main/java/com/swipelab/gamification/dto/GamificationUserInfoResponse.java
+++ b/backend/src/main/java/com/swipelab/gamification/dto/GamificationUserInfoResponse.java
@@ -9,6 +9,7 @@ public class GamificationUserInfoResponse {
     private long score;
     private String badge;
     private int currentStreak;
+    private int longestStreak;
 }
 
 
diff --git a/backend/src/main/java/com/swipelab/tasks/application/TaskService.java b/backend/src/main/java/com/swipelab/tasks/application/TaskService.java
index 5de06e3..f3f79e0 100644
--- a/backend/src/main/java/com/swipelab/tasks/application/TaskService.java
+++ b/backend/src/main/java/com/swipelab/tasks/application/TaskService.java
@@ -25,6 +25,10 @@
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.security.access.AccessDeniedException;
 import com.swipelab.auth.application.SecurityAuthorizationService;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.cache.annotation.CacheEvict;
+import org.springframework.cache.annotation.Caching;
+import com.swipelab.config.CacheConfig;
 
 import java.util.Collections;
 import java.util.List;
@@ -72,7 +76,7 @@ public TaskPageResponse getTasksForUser(String username, Pageable pageable) {
                 pageable);
 
         List<TaskResponse> taskResponses = taskPage.getContent().stream()
-                .map(task -> taskMapper.toResponse(task, true)) // assignedToUser = true
+                .map(task -> taskMapper.toResponse(task, true, buildProgress(task.getId()))) // assignedToUser = true
                 .collect(Collectors.toList());
 
         return TaskPageResponse.builder()
@@ -84,6 +88,7 @@ public TaskPageResponse getTasksForUser(String username, Pageable pageable) {
                 .build();
     }
 
+    @Cacheable(value = CacheConfig.CACHE_TASK_DETAILS, key = "#taskId + '-' + #username")
     @Transactional(readOnly = true)
     public TaskResponse getTaskForUser(Long taskId, String username) {
         Task task = getTask(taskId);
@@ -119,7 +124,7 @@ public TaskResponse getTaskForUser(Long taskId, String username) {
             throw new ResourceNotFoundException("Task not found or access denied");
         }
 
-        return taskMapper.toResponse(task, true);
+        return taskMapper.toResponse(task, true, buildProgress(task.getId()));
     }
 
     @Transactional(readOnly = true)
@@ -140,7 +145,7 @@ public TaskPageResponse getExploreTasksForUser(String username, Pageable pageabl
                 pageable);
 
         List<TaskResponse> taskResponses = taskPage.getContent().stream()
-                .map(task -> taskMapper.toResponse(task, false))
+                .map(task -> taskMapper.toResponse(task, false, buildProgress(task.getId())))
                 .collect(Collectors.toList());
 
         return TaskPageResponse.builder()
@@ -152,6 +157,10 @@ public TaskPageResponse getExploreTasksForUser(String username, Pageable pageabl
                 .build();
     }
 
+    @Caching(evict = {
+        @CacheEvict(value = CacheConfig.CACHE_ACTIVE_TASKS, allEntries = true),
+        @CacheEvict(value = CacheConfig.CACHE_TASK_DETAILS, allEntries = true)
+    })
     @Transactional
     public TaskResponse assignTaskToUser(Long taskId, String username) {
         Task task = getTask(taskId);
@@ -170,7 +179,7 @@ public TaskResponse assignTaskToUser(Long taskId, String username) {
         }
 
         task.getAssignedUsernames().add(username);
-        return taskMapper.toResponse(task, true);
+        return taskMapper.toResponse(task, true, buildProgress(task.getId()));
     }
 
     // =========================
@@ -188,6 +197,7 @@ public List<com.swipelab.integration.stardbi.dto.ExternalExperimentDto> getExper
         }
     }
 
+    @Cacheable(value = CacheConfig.CACHE_ACTIVE_TASKS, key = "#username")
     @Transactional(readOnly = true)
     public List<TaskResponse> getResearcherDashboard(String username) {
         List<Task> tasks;
@@ -204,6 +214,7 @@ public List<TaskResponse> getResearcherDashboard(String username) {
                 .collect(Collectors.toList());
     }
 
+    @Cacheable(value = CacheConfig.CACHE_TASK_DETAILS, key = "#taskId + '-' + #username")
     @Transactional(readOnly = true)
     public TaskResponse getTaskDetailsResearcher(Long taskId, String username) {
         Task task = getTask(taskId);
@@ -211,6 +222,10 @@ public TaskResponse getTaskDetailsResearcher(Long taskId, String username) {
         return taskMapper.toResponse(task, false, buildProgress(taskId));
     }
 
+    @Caching(evict = {
+        @CacheEvict(value = CacheConfig.CACHE_ACTIVE_TASKS, allEntries = true),
+        @CacheEvict(value = CacheConfig.CACHE_TASK_DETAILS, allEntries = true)
+    })
     @Transactional
     public TaskResponse createTask(CreateTaskRequest request, String username) {
         // Validate uniqueness
@@ -261,6 +276,10 @@ public TaskResponse createTask(CreateTaskRequest request, String username) {
         return mapToResponse(task);
     }
 
+    @Caching(evict = {
+        @CacheEvict(value = CacheConfig.CACHE_ACTIVE_TASKS, allEntries = true),
+        @CacheEvict(value = CacheConfig.CACHE_TASK_DETAILS, allEntries = true)
+    })
     @Transactional
     public TaskResponse archiveTask(Long taskId, String username) {
         Task task = getTask(taskId);
@@ -269,6 +288,10 @@ public TaskResponse archiveTask(Long taskId, String username) {
         return mapToResponse(task);
     }
 
+    @Caching(evict = {
+        @CacheEvict(value = CacheConfig.CACHE_ACTIVE_TASKS, allEntries = true),
+        @CacheEvict(value = CacheConfig.CACHE_TASK_DETAILS, allEntries = true)
+    })
     @Transactional
     public TaskResponse activateTask(Long taskId, String username) {
         Task task = getTask(taskId);
@@ -277,6 +300,10 @@ public TaskResponse activateTask(Long taskId, String username) {
         return mapToResponse(task);
     }
 
+    @Caching(evict = {
+        @CacheEvict(value = CacheConfig.CACHE_ACTIVE_TASKS, allEntries = true),
+        @CacheEvict(value = CacheConfig.CACHE_TASK_DETAILS, allEntries = true)
+    })
     @Transactional
     public TaskResponse pauseTask(Long taskId, String username) {
         Task task = getTask(taskId);
@@ -285,6 +312,10 @@ public TaskResponse pauseTask(Long taskId, String username) {
         return mapToResponse(task);
     }
 
+    @Caching(evict = {
+        @CacheEvict(value = CacheConfig.CACHE_ACTIVE_TASKS, allEntries = true),
+        @CacheEvict(value = CacheConfig.CACHE_TASK_DETAILS, allEntries = true)
+    })
     @Transactional
     public TaskResponse updateTask(Long taskId, UpdateTaskRequest request, String username) {
         Task task = getTask(taskId);
diff --git a/backend/src/main/java/com/swipelab/users/application/UserService.java b/backend/src/main/java/com/swipelab/users/application/UserService.java
index 06ce64c..162c628 100644
--- a/backend/src/main/java/com/swipelab/users/application/UserService.java
+++ b/backend/src/main/java/com/swipelab/users/application/UserService.java
@@ -108,6 +108,7 @@ public List<UserProfileResponse> getUsersByRole(String roleName) {
         try {
             com.swipelab.model.enums.UserRole role = com.swipelab.model.enums.UserRole.valueOf(roleName.toUpperCase());
             return userRepository.findByRole(role).stream()
+                    .filter(user -> !securityAuthorizationService.isSuperAdmin(user.getUsername()))
                     .map(authMapper::toUserProfileResponse)
                     .collect(Collectors.toList());
         } catch (IllegalArgumentException e) {
diff --git a/backend/src/test/java/com/swipelab/analytics/application/AnalyticsServiceTest.java b/backend/src/test/java/com/swipelab/analytics/application/AnalyticsServiceTest.java
index 9fa54b3..a53e674 100644
--- a/backend/src/test/java/com/swipelab/analytics/application/AnalyticsServiceTest.java
+++ b/backend/src/test/java/com/swipelab/analytics/application/AnalyticsServiceTest.java
@@ -7,6 +7,7 @@
 import com.swipelab.analytics.infrastructure.*;
 import com.swipelab.classification.domain.core.Classification.UserResponse;
 import com.swipelab.classification.infrastructure.ClassificationRepository;
+import com.swipelab.classification.infrastructure.ConsensusResultRepository;
 import com.swipelab.classification.infrastructure.ImageRepository;
 import com.swipelab.analytics.dto.DashboardStatsResponse;
 import com.swipelab.analytics.dto.UserPerformanceResponse;
@@ -42,6 +43,7 @@ class AnalyticsServiceTest {
     @Mock private UserRepository userRepository;
     @Mock private TaskRepository taskRepository;
     @Mock private ImageRepository imageRepository;
+    @Mock private ConsensusResultRepository consensusResultRepository;
 
     @InjectMocks
     private AnalyticsService analyticsService;
@@ -54,6 +56,7 @@ void getUserProgress_happyFlow_returnsCorrectAccuracy() {
         Object[] row = {10L, 8L};
         when(userDailyStatsRepository.getProgressSince(eq("alice"), any(LocalDate.class)))
                 .thenReturn(row);
+        when(classificationFactRepository.getUserAccuracy("alice")).thenReturn(0.8);
 
         UserProgressResponse result = analyticsService.getUserProgress("alice");
 
@@ -66,6 +69,7 @@ void getUserProgress_edgeCase_noData_returnsZeros() {
         // Repository returns null result when the user has no data
         when(userDailyStatsRepository.getProgressSince(eq("ghost"), any(LocalDate.class)))
                 .thenReturn(null);
+        when(classificationFactRepository.getUserAccuracy("ghost")).thenReturn(null);
 
         UserProgressResponse result = analyticsService.getUserProgress("ghost");
 
@@ -160,8 +164,8 @@ void getPlatformOverview_edgeCase_noDataYet_returnsZeroFilled() {
 
     @Test
     void getUserPerformanceMetrics_happyFlow_mapsAggregationCorrectly() {
-        // (userId, total, correct, avgCredibility)
-        Object[] row = {"alice", 50L, 40L, 0.85};
+        // (userId, total, correct, goldTotal, avgCredibility)
+        Object[] row = {"alice", 100L, 40L, 50L, 0.85};
         List<Object[]> perfRows = new java.util.ArrayList<>();
         perfRows.add(row);
         when(classificationFactRepository.getUserPerformanceAggregation(eq(1L)))
@@ -172,7 +176,8 @@ void getUserPerformanceMetrics_happyFlow_mapsAggregationCorrectly() {
         assertEquals(1, result.size());
         UserPerformanceResponse resp = result.get(0);
         assertEquals("alice", resp.getUsername());
-        assertEquals(50, resp.getTotalClassifications());
+        assertEquals(100, resp.getTotalClassifications());
+        assertEquals(50, resp.getGoldImageClassifications());
         assertEquals(0.85, resp.getCredibilityScore(), 0.001);
         assertEquals(0.8, resp.getGoldAccuracy(), 0.001); // 40/50
     }
@@ -192,7 +197,7 @@ void getUserPerformanceMetrics_edgeCase_nullTaskId_returnsAllUsers() {
 
     @Test
     void getTopPerformers_happyFlow_returnsLimitedList() {
-        Object[] row = {"bob", 100L, 90L, 0.92};
+        Object[] row = {"bob", 200L, 90L, 100L, 0.92};
         List<Object[]> topRows = new java.util.ArrayList<>();
         topRows.add(row);
         when(classificationFactRepository.getTopPerformersAggregation(any(Pageable.class)))
@@ -233,8 +238,9 @@ void getGlobalStats_happyFlow_returnsCorrectCounts() {
 
     @Test
     void getTaskAnalytics_happyFlow_computesProgressFromImageCounts() {
-        // 200 total crops in the task, 50 of them classified → 25 % complete
-        when(classificationFactRepository.countCompletedImages(1L)).thenReturn(50L);
+        // 200 total crops in the task, 50 of them classified, 5 completed → 2.5 % complete
+        when(classificationFactRepository.countDistinctImagesByTaskId(1L)).thenReturn(50L);
+        when(consensusResultRepository.countCompletedImagesByTaskId(1L)).thenReturn(5L);
         when(classificationFactRepository.findByTaskId(1L)).thenReturn(Collections.emptyList());
         when(taskSpeciesStatsRepository.findByTaskId(1L)).thenReturn(Collections.emptyList());
         when(imageRepository.countByTaskId(1L)).thenReturn(200L);
@@ -244,14 +250,15 @@ void getTaskAnalytics_happyFlow_computesProgressFromImageCounts() {
         TaskAnalyticsResponse.Progress progress = response.getProgress();
         assertEquals(200, progress.getTotalImages());
         assertEquals(50, progress.getImagesClassified());
-        assertEquals(50, progress.getCompletedImages());
-        assertEquals(25.0, progress.getPercentComplete(), 0.001);
+        assertEquals(5, progress.getCompletedImages());
+        assertEquals(2.5, progress.getPercentComplete(), 0.001);
     }
 
     @Test
     void getTaskAnalytics_edgeCase_noImages_returnsZeroPercent() {
         // No crops imported yet → avoid division by zero, report 0 %
-        when(classificationFactRepository.countCompletedImages(2L)).thenReturn(0L);
+        when(classificationFactRepository.countDistinctImagesByTaskId(2L)).thenReturn(0L);
+        when(consensusResultRepository.countCompletedImagesByTaskId(2L)).thenReturn(0L);
         when(classificationFactRepository.findByTaskId(2L)).thenReturn(Collections.emptyList());
         when(taskSpeciesStatsRepository.findByTaskId(2L)).thenReturn(Collections.emptyList());
         when(imageRepository.countByTaskId(2L)).thenReturn(0L);
diff --git a/backend/src/test/java/com/swipelab/config/CacheControlInterceptorTest.java b/backend/src/test/java/com/swipelab/config/CacheControlInterceptorTest.java
index 39e4f4b..383a5bd 100644
--- a/backend/src/test/java/com/swipelab/config/CacheControlInterceptorTest.java
+++ b/backend/src/test/java/com/swipelab/config/CacheControlInterceptorTest.java
@@ -35,17 +35,19 @@ private void handle(String method, String path) throws Exception {
     // ── Happy paths ────────────────────────────────────────────────────────────
 
     @Test
-    void GET_tasksList_ShouldSetNoStore() throws Exception {
-        // my-tasks is per-user and mutates on self-assignment — must never be browser-cached
+    void GET_tasksList_ShouldSetNoCachePrivate() throws Exception {
+        // my-tasks is per-user and uses ETag for revalidation
         handle("GET", "/api/v1/tasks/my-tasks");
-        assertThat(response.getHeader("Cache-Control")).isEqualTo("no-store");
+        assertThat(response.getHeader("Cache-Control")).contains("no-cache");
+        assertThat(response.getHeader("Cache-Control")).contains("private");
     }
 
     @Test
-    void GET_availableTasks_ShouldSetNoStore() throws Exception {
-        // available-tasks shrinks immediately after assignment — must never be browser-cached
+    void GET_availableTasks_ShouldSetNoCachePrivate() throws Exception {
+        // available-tasks uses ETag for revalidation
         handle("GET", "/api/v1/tasks/available-tasks");
-        assertThat(response.getHeader("Cache-Control")).isEqualTo("no-store");
+        assertThat(response.getHeader("Cache-Control")).contains("no-cache");
+        assertThat(response.getHeader("Cache-Control")).contains("private");
     }
 
     @Test
diff --git a/backend/src/test/java/com/swipelab/tasks/application/TaskServiceTest.java b/backend/src/test/java/com/swipelab/tasks/application/TaskServiceTest.java
index 67f0438..fb480e4 100644
--- a/backend/src/test/java/com/swipelab/tasks/application/TaskServiceTest.java
+++ b/backend/src/test/java/com/swipelab/tasks/application/TaskServiceTest.java
@@ -102,7 +102,7 @@ void getTasksForUser_ShouldReturnTasks_WhenGroupsMatch() {
         Page<Task> taskPage = new PageImpl<>(Collections.singletonList(task), pageable, 1);
         
         when(taskRepository.findAccessibleTasksForUser(eq(TaskStatus.ACTIVE), eq("testuser"), anySet(), eq(pageable))).thenReturn(taskPage);
-        when(taskMapper.toResponse(any(Task.class), eq(true))).thenReturn(taskResponse);
+        when(taskMapper.toResponse(any(Task.class), eq(true), any(TaskProgressResponse.class))).thenReturn(taskResponse);
 
         TaskPageResponse response = taskService.getTasksForUser("testuser", pageable);
 
@@ -130,7 +130,7 @@ void getTasksForUser_ShouldReturnEmpty_WhenNoGroups() {
     void getTaskForUser_ShouldReturnTask_WhenActiveAndAssigned() {
         when(taskRepository.findById(1L)).thenReturn(Optional.of(task));
         when(recipientGroupRepository.findByUsers_Username("testuser")).thenReturn(Collections.singletonList(group));
-        when(taskMapper.toResponse(task, true)).thenReturn(taskResponse);
+        when(taskMapper.toResponse(eq(task), eq(true), any(TaskProgressResponse.class))).thenReturn(taskResponse);
 
         TaskResponse response = taskService.getTaskForUser(1L, "testuser");
 
@@ -300,7 +300,7 @@ void assignTaskToUser_ShouldAddUsername_WhenNotYetAssigned() {
         task.setAssignedUsernames(new ArrayList<>());
         when(taskRepository.findById(1L)).thenReturn(Optional.of(task));
         when(taskRepository.existsByIdAndUsernameInAssignedUsers(1L, "testuser")).thenReturn(false);
-        when(taskMapper.toResponse(task, true)).thenReturn(taskResponse);
+        when(taskMapper.toResponse(eq(task), eq(true), any(TaskProgressResponse.class))).thenReturn(taskResponse);
 
         TaskResponse response = taskService.assignTaskToUser(1L, "testuser");
 
diff --git a/backend/src/test/java/com/swipelab/users/application/UserServiceTest.java b/backend/src/test/java/com/swipelab/users/application/UserServiceTest.java
index 3bb4471..95659f8 100644
--- a/backend/src/test/java/com/swipelab/users/application/UserServiceTest.java
+++ b/backend/src/test/java/com/swipelab/users/application/UserServiceTest.java
@@ -140,6 +140,30 @@ void getUserCredibility_ShouldReturnScore() {
         assertEquals(0.85, score);
     }
 
+    @Test
+    void getUsersByRole_ShouldReturnList_ExcludingSuperAdmin() {
+        User superAdmin = new User();
+        superAdmin.setUsername("superadmin");
+        
+        when(userRepository.findByRole(com.swipelab.model.enums.UserRole.RESEARCHER))
+                .thenReturn(List.of(user, superAdmin));
+        when(securityAuthorizationService.isSuperAdmin("testuser")).thenReturn(false);
+        when(securityAuthorizationService.isSuperAdmin("superadmin")).thenReturn(true);
+        when(authMapper.toUserProfileResponse(user)).thenReturn(profileResponse);
+
+        List<UserProfileResponse> responses = userService.getUsersByRole("RESEARCHER");
+
+        assertEquals(1, responses.size());
+        assertEquals("testuser", responses.get(0).getUsername());
+        verify(securityAuthorizationService, times(1)).isSuperAdmin("testuser");
+        verify(securityAuthorizationService, times(1)).isSuperAdmin("superadmin");
+    }
+
+    @Test
+    void getUsersByRole_ShouldThrowException_WhenRoleInvalid() {
+        assertThrows(ResourceNotFoundException.class, () -> userService.getUsersByRole("INVALID_ROLE"));
+    }
+
     @Test
     void getAllUsers_ShouldReturnList() {
         when(userRepository.findAll()).thenReturn(Collections.singletonList(user));
diff --git a/frontend/App.tsx b/frontend/App.tsx
index 2735774..e01ee41 100644
--- a/frontend/App.tsx
+++ b/frontend/App.tsx
@@ -10,6 +10,7 @@ import Toast from 'react-native-toast-message';
 import { useAppStateStore } from "@/stores/appStateStore";
 import { MaintenanceScreen } from "@/screens/shared/MaintenanceScreen";
 import { useHealthCheck } from "@/hooks/useHealthCheck";
+import GlobalDownloadToast from "@/components/ui/GlobalDownloadToast";
 
 export default function App() {
 
@@ -39,6 +40,7 @@ export default function App() {
           </GestureHandlerRootView>
         </View>
       </QueryClientProvider>
+      <GlobalDownloadToast />
       <Toast />
     </GlobalErrorBoundary>
   );
diff --git a/frontend/app/api/apiEndpoints.ts b/frontend/app/api/apiEndpoints.ts
index 6faaf8f..69ce7f7 100644
--- a/frontend/app/api/apiEndpoints.ts
+++ b/frontend/app/api/apiEndpoints.ts
@@ -1,4 +1,7 @@
 export const API_ENDPOINTS = {
+    SYSTEM: {
+        HEALTH: '/health',
+    },
     AUTH: {
         LOGIN: '/api/v1/auth/login',
         REGISTER: '/api/v1/auth/register',
diff --git a/frontend/app/api/apiFetch.ts b/frontend/app/api/apiFetch.ts
index 099de11..76c3e0c 100644
--- a/frontend/app/api/apiFetch.ts
+++ b/frontend/app/api/apiFetch.ts
@@ -92,14 +92,33 @@ export async function apiFetch(
     console.log("[apiFetch] Full exact URL being fetch'ed:", fullUrl);
   }
 
-  const response = await fetch(fullUrl, {
-    ...init,
-    credentials: "include", // Required for HttpOnly cookies on web
-    headers: {
-      ...(init?.headers ?? {}),
-      ...(token ? { Authorization: `Bearer ${token}` } : {}),
-    },
-  });
+  let response: Response;
+  try {
+    response = await fetch(fullUrl, {
+      ...init,
+      credentials: "include", // Required for HttpOnly cookies on web
+      headers: {
+        ...(init?.headers ?? {}),
+        ...(token ? { Authorization: `Bearer ${token}` } : {}),
+      },
+    });
+  } catch (err) {
+    // Network error (e.g., ERR_CONNECTION_REFUSED, offline)
+    (async () => {
+      try {
+        const healthRes = await fetch(backendUrl + API_ENDPOINTS.SYSTEM.HEALTH, { method: 'GET' });
+        if (!healthRes.ok) {
+          const { useAppStateStore } = require('@/stores/appStateStore');
+          useAppStateStore.getState().setMaintenanceMode(true);
+        }
+      } catch (e) {
+        // Backend is completely unreachable
+        const { useAppStateStore } = require('@/stores/appStateStore');
+        useAppStateStore.getState().setMaintenanceMode(true);
+      }
+    })();
+    throw err;
+  }
 
   if (response.status === 401) {
     // Check for Stardbi session expiration before attempting refresh
@@ -195,8 +214,8 @@ export async function apiFetch(
     }
   }
 
-  // Handle generic errors (non-401, non-403) with a Toast
-  if (!response.ok && response.status !== 401 && response.status !== 403 && response.status !== 500) {
+  // Handle generic errors (non-401, non-403) with a Toast, excluding 5xx errors which are handled below
+  if (!response.ok && response.status !== 401 && response.status !== 403 && response.status < 500) {
     const urlString = input.toString();
     if (!urlString.includes('/login') && !urlString.includes('/refresh')) {
       Toast.show({
@@ -209,8 +228,26 @@ export async function apiFetch(
 
   // 500 Maintenance Mode handling
   if (response.status >= 500) {
-    const { useAppStateStore } = require('@/stores/appStateStore');
-    useAppStateStore.getState().setMaintenanceMode(true);
+    (async () => {
+      try {
+        const healthRes = await fetch(backendUrl + API_ENDPOINTS.SYSTEM.HEALTH, { method: 'GET' });
+        if (!healthRes.ok) {
+          const { useAppStateStore } = require('@/stores/appStateStore');
+          useAppStateStore.getState().setMaintenanceMode(true);
+        } else {
+          // The backend is alive, it was just an isolated 500 error.
+          Toast.show({
+            type: 'error',
+            text1: 'Server Error',
+            text2: 'An unexpected internal error occurred.',
+          });
+        }
+      } catch (e) {
+        // Fetch failed entirely
+        const { useAppStateStore } = require('@/stores/appStateStore');
+        useAppStateStore.getState().setMaintenanceMode(true);
+      }
+    })();
   }
   
   return response;
diff --git a/frontend/app/api/queries.ts b/frontend/app/api/queries.ts
index a91317f..b81ccd0 100644
--- a/frontend/app/api/queries.ts
+++ b/frontend/app/api/queries.ts
@@ -7,7 +7,7 @@ export const QUERY_KEYS = {
   myTasks: ['tasks', 'my'],
   availableTasks: ['tasks', 'available'],
   dashboardTasks: ['tasks', 'dashboard'],
-  taskDetails: (id: string | number) => ['tasks', id],
+  taskDetails: (id: string | number) => ['tasks', Number(id)],
   experiments: ['tasks', 'experiments'],
   
   // User Profile
@@ -92,7 +92,7 @@ export const useAllStatistics = () => {
             fetchJson(API_ENDPOINTS.STATISTICS.VS_EXPERTS),
             fetchJson(API_ENDPOINTS.STATISTICS.VS_USERS),
             fetchJson(API_ENDPOINTS.STATISTICS.BREAKDOWN),
-            fetchJson(API_ENDPOINTS.GAMIFICATION.USER_INFO).catch(() => ({ score: 0, badge: null, currentStreak: 0 })),
+            fetchJson(API_ENDPOINTS.GAMIFICATION.USER_INFO).catch(() => ({ score: 0, badge: null, currentStreak: 0, longestStreak: 0 })),
         ]);
         return { summary, vsExperts, vsUsers, breakdown, userInfo };
     },
@@ -311,7 +311,17 @@ export const useUpdateTaskStatus = () => {
     },
     onSuccess: (updatedTask, { taskId }) => {
       queryClient.setQueryData(QUERY_KEYS.taskDetails(taskId), updatedTask);
-      queryClient.invalidateQueries({ queryKey: QUERY_KEYS.dashboardTasks });
+      queryClient.setQueryData(QUERY_KEYS.dashboardTasks, (oldData: any) => {
+        if (!Array.isArray(oldData)) return oldData;
+        return oldData.map((task: any) =>
+          task.taskId === Number(taskId) ? updatedTask : task
+        );
+      });
+    },
+    onSettled: (data, error, { taskId }) => {
+      // Broadly invalidate to ensure all lists and analytics screens reflect the new status
+      queryClient.invalidateQueries({ queryKey: ['tasks'] });
+      queryClient.invalidateQueries({ queryKey: ['analytics'] });
     }
   });
 };
diff --git a/frontend/app/components/researcher/ExportModal.tsx b/frontend/app/components/researcher/ExportModal.tsx
index 58b0590..94396e6 100644
--- a/frontend/app/components/researcher/ExportModal.tsx
+++ b/frontend/app/components/researcher/ExportModal.tsx
@@ -18,6 +18,8 @@ import { useThemeStore } from '@/stores/themeStore';
 import MultiSelect, { MultiSelectOption } from '@/components/ui/MultiSelect';
 import { useAdminTasks, useExportClassificationsCsv } from '@/api/queries';
 import { downloadCsvBlob } from '@/services/csvDownload';
+import { useDownloadStore } from '@/stores/downloadStore';
+import Toast from 'react-native-toast-message';
 
 interface ExportModalProps {
   visible: boolean;
@@ -60,22 +62,42 @@ export default function ExportModal({ visible, onClose }: ExportModalProps) {
     }
   };
 
+  const { addTasks, removeTasks } = useDownloadStore();
+
   const handleExport = async () => {
     if (selectedTaskIds.length === 0) return;
 
+    // Build the list of tasks to export based on selected IDs
+    const tasksToExport = selectedTaskIds.map((id) => {
+      const numericId = Number(id);
+      const taskOpt = taskOptions.find(t => t.id === numericId);
+      return { taskId: numericId, taskName: taskOpt?.label ?? `Task #${numericId}` };
+    });
+
+    const numericIds = tasksToExport.map(t => t.taskId);
+
+    // Register tasks in global background download store
+    addTasks(tasksToExport);
+
+    // Close the modal immediately to allow background operation
+    setSelectedTaskIds([]);
+    onClose();
+
     try {
-      const numericIds = selectedTaskIds.map((id) => Number(id));
       const blob = await exportMutation.mutateAsync(numericIds);
 
       const today = new Date().toISOString().slice(0, 10);
       const filename = `swipelab_classifications_export_${today}.csv`;
       await downloadCsvBlob(blob, filename);
-
-      Alert.alert('Success', `Exported ${selectedTaskIds.length} task(s) to CSV.`);
-      setSelectedTaskIds([]);
-      onClose();
     } catch (err: any) {
-      Alert.alert('Export Failed', err?.message ?? 'Something went wrong. Please try again.');
+      Toast.show({
+        type: 'error',
+        text1: 'Export Failed',
+        text2: err?.message ?? 'Something went wrong. Please try again.',
+      });
+    } finally {
+      // Remove tasks from active background list
+      removeTasks(numericIds);
     }
   };
 
diff --git a/frontend/app/components/researcher/LabelDistributionBar.tsx b/frontend/app/components/researcher/LabelDistributionBar.tsx
index 567f2d0..3058df5 100644
--- a/frontend/app/components/researcher/LabelDistributionBar.tsx
+++ b/frontend/app/components/researcher/LabelDistributionBar.tsx
@@ -11,8 +11,8 @@ type Props = {
 const LABEL_CONFIG: Record<string, { color: string; emoji: string }> = {
   YES:       { color: '#10B981', emoji: '✅' },
   NO:        { color: '#EF4444', emoji: '❌' },
-  DONT_KNOW: { color: '#9CA3AF', emoji: '❓' },
-  TRASH:     { color: '#F59E0B', emoji: '🗑️' },
+  DONT_KNOW: { color: '#F59E0B', emoji: '❓' },
+  TRASH:     { color: '#9CA3AF', emoji: '🗑️' },
 };
 
 export default function LabelDistributionBar({ data }: Props) {
diff --git a/frontend/app/components/researcher/TaskCard.tsx b/frontend/app/components/researcher/TaskCard.tsx
index 82e717c..6643528 100644
--- a/frontend/app/components/researcher/TaskCard.tsx
+++ b/frontend/app/components/researcher/TaskCard.tsx
@@ -118,53 +118,57 @@ export default function TaskCard({ task, onPress, onEdit, onToggleStatus, onArch
         </View>
 
         {/* Divider */}
-        <View style={[styles.divider, { backgroundColor: isDark ? themeColors.border : '#DBEAFE' }]} />
+        {task.status !== 'ARCHIVED' && (
+          <>
+            <View style={[styles.divider, { backgroundColor: isDark ? themeColors.border : '#DBEAFE' }]} />
 
-        {/* Action row */}
-        <View style={styles.actions}>
-          {/* Toggle status */}
-          {isProcessing ? (
-            <View style={styles.actionChip}>
-              <Ionicons name="cloud-download-outline" size={14} color="#3B82F6" />
-              <Text style={[styles.actionChipText, { color: '#3B82F6' }]}>Importing…</Text>
-            </View>
-          ) : (
-            <TouchableOpacity
-              style={[
-                styles.actionChip,
-                { backgroundColor: isActive ? '#FEF3C7' : '#D1FAE5' },
-              ]}
-              onPress={(e) => { e.stopPropagation(); onToggleStatus(); }}
-            >
-              <Ionicons
-                name={isActive ? 'pause-circle-outline' : 'play-circle-outline'}
-                size={15}
-                color={isActive ? '#F59E0B' : '#10B981'}
-              />
-              <Text style={[styles.actionChipText, { color: isActive ? '#F59E0B' : '#10B981' }]}>
-                {isActive ? 'Pause' : 'Resume'}
-              </Text>
-            </TouchableOpacity>
-          )}
+            {/* Action row */}
+            <View style={styles.actions}>
+              {/* Toggle status */}
+              {isProcessing ? (
+                <View style={styles.actionChip}>
+                  <Ionicons name="cloud-download-outline" size={14} color="#3B82F6" />
+                  <Text style={[styles.actionChipText, { color: '#3B82F6' }]}>Importing…</Text>
+                </View>
+              ) : (
+                <TouchableOpacity
+                  style={[
+                    styles.actionChip,
+                    { backgroundColor: isActive ? '#FEF3C7' : '#D1FAE5' },
+                  ]}
+                  onPress={(e) => { e.stopPropagation(); onToggleStatus(); }}
+                >
+                  <Ionicons
+                    name={isActive ? 'pause-circle-outline' : 'play-circle-outline'}
+                    size={15}
+                    color={isActive ? '#F59E0B' : '#10B981'}
+                  />
+                  <Text style={[styles.actionChipText, { color: isActive ? '#F59E0B' : '#10B981' }]}>
+                    {isActive ? 'Pause' : 'Resume'}
+                  </Text>
+                </TouchableOpacity>
+              )}
 
-          <View style={styles.iconActions}>
-            <TouchableOpacity
-              disabled={isProcessing}
-              style={styles.iconBtn}
-              onPress={(e) => { e.stopPropagation(); onEdit(); }}
-            >
-              <Ionicons name="create-outline" size={20} color="#3B82F6" />
-            </TouchableOpacity>
+              <View style={styles.iconActions}>
+                <TouchableOpacity
+                  disabled={isProcessing}
+                  style={styles.iconBtn}
+                  onPress={(e) => { e.stopPropagation(); onEdit(); }}
+                >
+                  <Ionicons name="create-outline" size={20} color="#3B82F6" />
+                </TouchableOpacity>
 
-            <TouchableOpacity
-              disabled={isProcessing}
-              style={styles.iconBtn}
-              onPress={(e) => { e.stopPropagation(); onArchive(); }}
-            >
-              <Ionicons name="archive-outline" size={20} color={themeColors.textSecondary} />
-            </TouchableOpacity>
-          </View>
-        </View>
+                <TouchableOpacity
+                  disabled={isProcessing}
+                  style={styles.iconBtn}
+                  onPress={(e) => { e.stopPropagation(); onArchive(); }}
+                >
+                  <Ionicons name="archive-outline" size={20} color={themeColors.textSecondary} />
+                </TouchableOpacity>
+              </View>
+            </View>
+          </>
+        )}
       </View>
     </TouchableOpacity>
   );
diff --git a/frontend/app/components/ui/ConfirmationModal.tsx b/frontend/app/components/ui/ConfirmationModal.tsx
new file mode 100644
index 0000000..44dafc3
--- /dev/null
+++ b/frontend/app/components/ui/ConfirmationModal.tsx
@@ -0,0 +1,124 @@
+import React from 'react';
+import { Modal, View, Text, TouchableOpacity, StyleSheet } from 'react-native';
+import { useThemeStore } from '@/stores/themeStore';
+import { Colors } from '../../../constants/theme';
+import { Ionicons } from '@expo/vector-icons';
+
+interface ConfirmationModalProps {
+  visible: boolean;
+  title: string;
+  message: string;
+  confirmText?: string;
+  cancelText?: string;
+  onConfirm: () => void;
+  onCancel: () => void;
+}
+
+export default function ConfirmationModal({
+  visible,
+  title,
+  message,
+  confirmText = 'Confirm',
+  cancelText = 'Cancel',
+  onConfirm,
+  onCancel,
+}: ConfirmationModalProps) {
+  const { theme } = useThemeStore();
+  const themeColors = Colors[theme as keyof typeof Colors];
+  const isDark = theme === 'dark';
+
+  if (!visible) return null;
+
+  return (
+    <Modal transparent visible={visible} animationType="fade" onRequestClose={onCancel}>
+      <View style={styles.overlay}>
+        <View style={[styles.card, { backgroundColor: isDark ? themeColors.card : '#FFF', borderColor: isDark ? themeColors.border : '#E5E7EB' }]}>
+          
+          <View style={styles.header}>
+            <Ionicons name="warning-outline" size={24} color="#EF4444" style={{ marginRight: 8 }} />
+            <Text style={[styles.title, { color: themeColors.text }]}>{title}</Text>
+          </View>
+          
+          <Text style={[styles.message, { color: themeColors.textSecondary }]}>
+            {message}
+          </Text>
+          
+          <View style={styles.actions}>
+            <TouchableOpacity style={[styles.btn, styles.cancelBtn, { borderColor: isDark ? themeColors.border : '#D1D5DB' }]} onPress={onCancel}>
+              <Text style={[styles.cancelBtnText, { color: themeColors.text }]}>{cancelText}</Text>
+            </TouchableOpacity>
+            
+            <TouchableOpacity style={[styles.btn, styles.confirmBtn]} onPress={onConfirm}>
+              <Text style={styles.confirmBtnText}>{confirmText}</Text>
+            </TouchableOpacity>
+          </View>
+
+        </View>
+      </View>
+    </Modal>
+  );
+}
+
+const styles = StyleSheet.create({
+  overlay: {
+    flex: 1,
+    backgroundColor: 'rgba(0, 0, 0, 0.5)',
+    justifyContent: 'center',
+    alignItems: 'center',
+    padding: 20,
+  },
+  card: {
+    width: '100%',
+    maxWidth: 400,
+    borderRadius: 16,
+    borderWidth: 1,
+    padding: 24,
+    shadowColor: '#000',
+    shadowOffset: { width: 0, height: 4 },
+    shadowOpacity: 0.25,
+    shadowRadius: 10,
+    elevation: 8,
+  },
+  header: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    marginBottom: 12,
+  },
+  title: {
+    fontSize: 20,
+    fontWeight: '700',
+  },
+  message: {
+    fontSize: 15,
+    lineHeight: 22,
+    marginBottom: 24,
+  },
+  actions: {
+    flexDirection: 'row',
+    justifyContent: 'flex-end',
+    gap: 12,
+  },
+  btn: {
+    paddingVertical: 10,
+    paddingHorizontal: 20,
+    borderRadius: 8,
+    alignItems: 'center',
+    justifyContent: 'center',
+  },
+  cancelBtn: {
+    backgroundColor: 'transparent',
+    borderWidth: 1,
+  },
+  confirmBtn: {
+    backgroundColor: '#EF4444',
+  },
+  cancelBtnText: {
+    fontSize: 15,
+    fontWeight: '600',
+  },
+  confirmBtnText: {
+    fontSize: 15,
+    fontWeight: '600',
+    color: '#FFF',
+  },
+});
diff --git a/frontend/app/components/ui/GlobalDownloadToast.tsx b/frontend/app/components/ui/GlobalDownloadToast.tsx
new file mode 100644
index 0000000..8b19987
--- /dev/null
+++ b/frontend/app/components/ui/GlobalDownloadToast.tsx
@@ -0,0 +1,118 @@
+import React, { useEffect, useRef, useState } from 'react';
+import { Animated, StyleSheet, Text, ActivityIndicator, Platform } from 'react-native';
+import { useDownloadStore } from '@/stores/downloadStore';
+import { Ionicons } from '@expo/vector-icons';
+import { Colors } from '../../../constants/theme';
+import { useThemeStore } from '@/stores/themeStore';
+
+export default function GlobalDownloadToast() {
+  const activeExports = useDownloadStore((state) => state.activeExports);
+  const { theme } = useThemeStore();
+  const themeColors = Colors[theme as keyof typeof Colors];
+  const isDark = theme === 'dark';
+
+  const [visible, setVisible] = useState(false);
+  const [completed, setCompleted] = useState(false);
+  const opacity = useRef(new Animated.Value(0)).current;
+
+  // Keep track of previous length to detect completion
+  const prevLengthRef = useRef(activeExports.length);
+  const timeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    const currentLength = activeExports.length;
+    
+    if (currentLength > 0) {
+      if (timeoutRef.current) clearTimeout(timeoutRef.current);
+      setVisible(true);
+      setCompleted(false);
+      
+      Animated.timing(opacity, {
+        toValue: 1,
+        duration: 300,
+        useNativeDriver: true,
+      }).start();
+    } else if (currentLength === 0 && prevLengthRef.current > 0) {
+      // Just finished
+      setCompleted(true);
+      
+      if (timeoutRef.current) clearTimeout(timeoutRef.current);
+      timeoutRef.current = setTimeout(() => {
+        Animated.timing(opacity, {
+          toValue: 0,
+          duration: 300,
+          useNativeDriver: true,
+        }).start(() => {
+          setVisible(false);
+          setCompleted(false);
+        });
+      }, 3000);
+    }
+    
+    prevLengthRef.current = currentLength;
+  }, [activeExports.length, opacity]);
+
+  if (!visible) return null;
+
+  let text = '';
+  if (completed) {
+    text = 'Download Complete';
+  } else {
+    const names = activeExports.map(t => t.taskName);
+    if (names.length === 1) {
+      text = `Downloading: ${names[0]}`;
+    } else if (names.length === 2) {
+      text = `Downloading: ${names[0]}, ${names[1]}`;
+    } else if (names.length > 2) {
+      text = `Downloading: ${names[0]}, ${names[1]} +${names.length - 2} more`;
+    }
+  }
+
+  return (
+    <Animated.View
+      style={[
+        styles.container,
+        {
+          opacity,
+          backgroundColor: isDark ? themeColors.card : '#FFFFFF',
+          borderColor: isDark ? themeColors.border : '#E5E7EB',
+          ...Platform.select({
+            web: { boxShadow: '0 4px 12px rgba(0,0,0,0.1)' },
+            default: { elevation: 6, shadowColor: '#000', shadowOffset: { width: 0, height: 4 }, shadowOpacity: 0.1, shadowRadius: 12 },
+          })
+        }
+      ]}
+    >
+      {completed ? (
+        <Ionicons name="checkmark-circle" size={20} color="#10B981" />
+      ) : (
+        <ActivityIndicator size="small" color="#3B82F6" />
+      )}
+      <Text style={[styles.text, { color: themeColors.text }]} numberOfLines={1}>
+        {text}
+      </Text>
+    </Animated.View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    position: 'absolute',
+    bottom: 90, // Above bottom toolbar
+    right: 20,
+    flexDirection: 'row',
+    alignItems: 'center',
+    paddingHorizontal: 16,
+    paddingVertical: 12,
+    borderRadius: 12,
+    borderWidth: 1,
+    gap: 10,
+    maxWidth: 300,
+    zIndex: 9999,
+  },
+  text: {
+    fontSize: 14,
+    fontWeight: '500',
+    flexShrink: 1,
+  }
+});
diff --git a/frontend/app/screens/researcher/AddTaskScreen.tsx b/frontend/app/screens/researcher/AddTaskScreen.tsx
index 96d2964..a635ded 100644
--- a/frontend/app/screens/researcher/AddTaskScreen.tsx
+++ b/frontend/app/screens/researcher/AddTaskScreen.tsx
@@ -18,7 +18,7 @@ import StepName from "@/components/researcher/addTask/StepName";
 import StepRecipients from "@/components/researcher/addTask/StepRecipients";
 import StepSpecies from "@/components/researcher/addTask/StepSpecies";
 import StepExperiments from "@/components/researcher/addTask/StepExperiments";
-import { useSpeciesPoolImages } from "@/api/queries";
+import { useSpeciesPoolImages, QUERY_KEYS } from "@/api/queries";
 
 const STEPS = ["Name", "Description", "Experiments", "Species", "Recipients", "Confirm"];
 
@@ -87,7 +87,12 @@ export default function AddTaskScreen({ route, navigation }: any) {
         }
         if (researchersRes.ok) {
           const researchers = await researchersRes.json();
-          setAvailableResearchers(researchers.map((r: any) => ({ id: r.username, label: r.displayName || r.username })));
+          const currentUser = queryClient.getQueryData<any>(QUERY_KEYS.userProfile);
+          setAvailableResearchers(
+            researchers
+              .filter((r: any) => !currentUser || r.username !== currentUser.username)
+              .map((r: any) => ({ id: r.username, label: r.displayName || r.username }))
+          );
         }
         setAvailableOptions(loaded);
       } catch (error) {
diff --git a/frontend/app/screens/researcher/AnalyticsScreen.tsx b/frontend/app/screens/researcher/AnalyticsScreen.tsx
index 1579288..923d5c9 100644
--- a/frontend/app/screens/researcher/AnalyticsScreen.tsx
+++ b/frontend/app/screens/researcher/AnalyticsScreen.tsx
@@ -233,7 +233,7 @@ export default function AnalyticsScreen({ navigation }: any) {
                 </Text>
                 <Text style={[styles.userStats, { color: themeColors.textSecondary }]}>
                   {user.totalClassifications} classifications •{' '}
-                  {(user.goldAccuracy ?? 0).toFixed(1)}% accuracy
+                  {((user.goldAccuracy ?? 0) * 100).toFixed(1)}% accuracy
                 </Text>
               </View>
               <View style={styles.credBox}>
diff --git a/frontend/app/screens/researcher/EditTaskScreen.tsx b/frontend/app/screens/researcher/EditTaskScreen.tsx
index 676d0d9..779d7ee 100644
--- a/frontend/app/screens/researcher/EditTaskScreen.tsx
+++ b/frontend/app/screens/researcher/EditTaskScreen.tsx
@@ -93,7 +93,12 @@ export default function EditTaskScreen({ route, navigation }: Props) {
         }
         if (researchersRes.ok) {
           const researchers = await researchersRes.json();
-          setAvailableResearchers(researchers.map((r: any) => ({ id: r.username, label: r.displayName || r.username })));
+          const currentUser = queryClient.getQueryData<any>(QUERY_KEYS.userProfile);
+          setAvailableResearchers(
+            researchers
+              .filter((r: any) => !currentUser || r.username !== currentUser.username)
+              .map((r: any) => ({ id: r.username, label: r.displayName || r.username }))
+          );
         }
         setAvailableOptions(loaded);
       } catch (error) {
@@ -244,6 +249,7 @@ export default function EditTaskScreen({ route, navigation }: Props) {
       await queryClient.invalidateQueries({ queryKey: QUERY_KEYS.taskDetails(taskId) });
       queryClient.invalidateQueries({ queryKey: ["tasks"] });
       queryClient.invalidateQueries({ queryKey: ["species", "pool"] });
+      queryClient.invalidateQueries({ queryKey: ["analytics"] });
 
       Alert.alert("Success", "Task updated successfully");
       navigation.navigate("TasksManagement");
diff --git a/frontend/app/screens/researcher/MaliciousLabelingConfigScreen.tsx b/frontend/app/screens/researcher/MaliciousLabelingConfigScreen.tsx
index 44f7212..bd2a9f8 100644
--- a/frontend/app/screens/researcher/MaliciousLabelingConfigScreen.tsx
+++ b/frontend/app/screens/researcher/MaliciousLabelingConfigScreen.tsx
@@ -102,6 +102,61 @@ const formToPayload = (form: ConfigForm) => ({
   warningCooldownMinutes:      parseInt(form.warningCooldownMinutes, 10),
 });
 
+// ── Sub-components (Extracted to prevent focus loss) ──────────────────────────
+
+const Field = ({
+  label, value, error, unit, keyboardType = 'numeric', colors, onChangeText,
+}: {
+  label: string; value: string; error?: string; unit?: string; keyboardType?: 'numeric' | 'decimal-pad'; colors: any; onChangeText: (val: string) => void;
+}) => (
+  <View style={s.fieldRow}>
+    <View style={s.fieldLabelWrap}>
+      <Text style={[s.fieldLabel, { color: colors.text }]}>{label}</Text>
+      {unit && <Text style={[s.fieldUnit, { color: colors.textSub }]}>{unit}</Text>}
+    </View>
+    <View style={[s.inputWrap, { backgroundColor: colors.inputBg, borderColor: error ? colors.error : colors.inputBorder }]}>
+      <TextInput
+        style={[s.input, { color: colors.text }]}
+        value={value}
+        onChangeText={(text) => {
+          const sanitized = keyboardType === 'decimal-pad' 
+            ? text.replace(/[^0-9.]/g, '') 
+            : text.replace(/[^0-9]/g, '');
+          onChangeText(sanitized);
+        }}
+        keyboardType={keyboardType}
+        placeholderTextColor={colors.textSub}
+      />
+    </View>
+    {error ? <Text style={[s.errorText, { color: colors.error }]}>{error}</Text> : null}
+  </View>
+);
+
+const SwitchField = ({ label, desc, value, colors, isDark, onValueChange }: { label: string; desc: string; value: boolean; colors: any; isDark: boolean; onValueChange: (val: boolean) => void }) => (
+  <View style={[s.switchRow, { backgroundColor: colors.card, borderColor: colors.cardBorder }]}>
+    <View style={s.switchTextWrap}>
+      <Text style={[s.switchLabel, { color: colors.text }]}>{label}</Text>
+      <Text style={[s.switchDesc, { color: colors.textSub }]}>{desc}</Text>
+    </View>
+    <Switch
+      value={value}
+      onValueChange={onValueChange}
+      trackColor={{ false: isDark ? '#374151' : '#d1d5db', true: colors.accent }}
+      thumbColor="#fff"
+    />
+  </View>
+);
+
+const Section = ({ title, icon, colors, children }: { title: string; icon: string; colors: any; children: React.ReactNode }) => (
+  <View style={[s.section, { backgroundColor: colors.card, borderColor: colors.cardBorder }]}>
+    <View style={s.sectionHeader}>
+      <Ionicons name={icon as any} size={18} color={colors.accent} style={{ marginRight: 8 }} />
+      <Text style={[s.sectionTitle, { color: colors.text }]}>{title}</Text>
+    </View>
+    {children}
+  </View>
+);
+
 // ── Main component ────────────────────────────────────────────────────────────
 
 export default function MaliciousLabelingConfigScreen() {
@@ -158,56 +213,6 @@ export default function MaliciousLabelingConfigScreen() {
     success:     '#22c55e',
   };
 
-  // ── Sub-components ─────────────────────────────────────────────────────────
-
-  const Field = ({
-    label, fieldKey, unit, keyboardType = 'numeric',
-  }: {
-    label: string; fieldKey: keyof ConfigForm; unit?: string; keyboardType?: 'numeric' | 'decimal-pad';
-  }) => (
-    <View style={s.fieldRow}>
-      <View style={s.fieldLabelWrap}>
-        <Text style={[s.fieldLabel, { color: c.text }]}>{label}</Text>
-        {unit && <Text style={[s.fieldUnit, { color: c.textSub }]}>{unit}</Text>}
-      </View>
-      <View style={[s.inputWrap, { backgroundColor: c.inputBg, borderColor: errors[fieldKey] ? c.error : c.inputBorder }]}>
-        <TextInput
-          style={[s.input, { color: c.text }]}
-          value={form ? String(form[fieldKey]) : ''}
-          onChangeText={v => { setForm(prev => prev ? { ...prev, [fieldKey]: v } : prev); setSaveError(''); }}
-          keyboardType={keyboardType}
-          placeholderTextColor={c.textSub}
-        />
-      </View>
-      {errors[fieldKey] ? <Text style={[s.errorText, { color: c.error }]}>{errors[fieldKey]}</Text> : null}
-    </View>
-  );
-
-  const SwitchField = ({ label, desc }: { label: string; desc: string }) => (
-    <View style={[s.switchRow, { backgroundColor: c.card, borderColor: c.cardBorder }]}>
-      <View style={s.switchTextWrap}>
-        <Text style={[s.switchLabel, { color: c.text }]}>{label}</Text>
-        <Text style={[s.switchDesc, { color: c.textSub }]}>{desc}</Text>
-      </View>
-      <Switch
-        value={form?.autoBanEnabled ?? true}
-        onValueChange={v => setForm(prev => prev ? { ...prev, autoBanEnabled: v } : prev)}
-        trackColor={{ false: isDark ? '#374151' : '#d1d5db', true: c.accent }}
-        thumbColor="#fff"
-      />
-    </View>
-  );
-
-  const Section = ({ title, icon, children }: { title: string; icon: string; children: React.ReactNode }) => (
-    <View style={[s.section, { backgroundColor: c.card, borderColor: c.cardBorder }]}>
-      <View style={s.sectionHeader}>
-        <Ionicons name={icon as any} size={18} color={c.accent} style={{ marginRight: 8 }} />
-        <Text style={[s.sectionTitle, { color: c.text }]}>{title}</Text>
-      </View>
-      {children}
-    </View>
-  );
-
   // ── Render ─────────────────────────────────────────────────────────────────
 
   if (isLoading || !form) {
@@ -258,9 +263,24 @@ export default function MaliciousLabelingConfigScreen() {
         )}
 
         {/* ── Credibility-based detection ─────────────────────── */}
-        <Section title="Credibility Detection" icon="shield-checkmark-outline">
-          <Field label="Malicious Threshold" fieldKey="maliciousThreshold" unit="score 0–100" keyboardType="decimal-pad" />
-          <Field label="Min Samples" fieldKey="maliciousMinSamples" unit="classifications" />
+        <Section title="Credibility Detection" icon="shield-checkmark-outline" colors={c}>
+          <Field 
+            label="Malicious Threshold" 
+            value={form.maliciousThreshold} 
+            error={errors.maliciousThreshold}
+            colors={c}
+            onChangeText={v => { setForm(prev => prev ? { ...prev, maliciousThreshold: v } : prev); setSaveError(''); }}
+            unit="score 0–100" 
+            keyboardType="decimal-pad" 
+          />
+          <Field 
+            label="Min Samples" 
+            value={form.maliciousMinSamples}
+            error={errors.maliciousMinSamples}
+            colors={c}
+            onChangeText={v => { setForm(prev => prev ? { ...prev, maliciousMinSamples: v } : prev); setSaveError(''); }}
+            unit="classifications" 
+          />
         </Section>
 
         {/* ── Auto-ban toggle ──────────────────────────────────── */}
@@ -271,22 +291,26 @@ export default function MaliciousLabelingConfigScreen() {
               ? 'Users are automatically banned when strikes reach the ban threshold.'
               : 'Auto-ban is OFF — strikes accumulate but no ban is issued.'
           }
+          value={form.autoBanEnabled}
+          colors={c}
+          isDark={isDark}
+          onValueChange={v => setForm(prev => prev ? { ...prev, autoBanEnabled: v } : prev)}
         />
 
         {/* ── Fraud detection (speed-based) ───────────────────── */}
-        <Section title="Fraud Detection — Speed Thresholds" icon="timer-outline">
-          <Field label="Min Response Time (Regular)" fieldKey="minResponseTimeMs" unit="ms" />
-          <Field label="Min Response Time (Researcher)" fieldKey="researcherMinResponseTimeMs" unit="ms" />
-          <Field label="Suspicious Count / Strike" fieldKey="suspiciousCountForStrike" unit="events" />
-          <Field label="Sliding Window" fieldKey="slidingWindowMinutes" unit="min" />
+        <Section title="Fraud Detection — Speed Thresholds" icon="timer-outline" colors={c}>
+          <Field label="Min Response Time (Regular)" value={form.minResponseTimeMs} error={errors.minResponseTimeMs} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, minResponseTimeMs: v } : prev); setSaveError(''); }} unit="ms" />
+          <Field label="Min Response Time (Researcher)" value={form.researcherMinResponseTimeMs} error={errors.researcherMinResponseTimeMs} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, researcherMinResponseTimeMs: v } : prev); setSaveError(''); }} unit="ms" />
+          <Field label="Suspicious Count / Strike" value={form.suspiciousCountForStrike} error={errors.suspiciousCountForStrike} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, suspiciousCountForStrike: v } : prev); setSaveError(''); }} unit="events" />
+          <Field label="Sliding Window" value={form.slidingWindowMinutes} error={errors.slidingWindowMinutes} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, slidingWindowMinutes: v } : prev); setSaveError(''); }} unit="min" />
         </Section>
 
         {/* ── Escalation ladder ────────────────────────────────── */}
-        <Section title="Escalation Ladder" icon="trending-up-outline">
-          <Field label="Strikes for Warning 1" fieldKey="strikesForWarning1" unit="strikes" />
-          <Field label="Strikes for Warning 2" fieldKey="strikesForWarning2" unit="strikes" />
-          <Field label="Strikes for Ban" fieldKey="strikesForBan" unit="strikes" />
-          <Field label="Warning Cooldown" fieldKey="warningCooldownMinutes" unit="min" />
+        <Section title="Escalation Ladder" icon="trending-up-outline" colors={c}>
+          <Field label="Strikes for Warning 1" value={form.strikesForWarning1} error={errors.strikesForWarning1} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, strikesForWarning1: v } : prev); setSaveError(''); }} unit="strikes" />
+          <Field label="Strikes for Warning 2" value={form.strikesForWarning2} error={errors.strikesForWarning2} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, strikesForWarning2: v } : prev); setSaveError(''); }} unit="strikes" />
+          <Field label="Strikes for Ban" value={form.strikesForBan} error={errors.strikesForBan} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, strikesForBan: v } : prev); setSaveError(''); }} unit="strikes" />
+          <Field label="Warning Cooldown" value={form.warningCooldownMinutes} error={errors.warningCooldownMinutes} colors={c} onChangeText={v => { setForm(prev => prev ? { ...prev, warningCooldownMinutes: v } : prev); setSaveError(''); }} unit="min" />
         </Section>
 
         {/* ── Save button ──────────────────────────────────────── */}
diff --git a/frontend/app/screens/researcher/TaskDetailsScreen.tsx b/frontend/app/screens/researcher/TaskDetailsScreen.tsx
index 28b148b..5e116a0 100644
--- a/frontend/app/screens/researcher/TaskDetailsScreen.tsx
+++ b/frontend/app/screens/researcher/TaskDetailsScreen.tsx
@@ -1,6 +1,6 @@
 import { Ionicons } from "@expo/vector-icons";
 import { NativeStackScreenProps } from "@react-navigation/native-stack";
-import React from "react";
+import React, { useState } from "react";
 import {
   ActivityIndicator,
   Image,
@@ -16,6 +16,7 @@ import { researcherStackParamList } from "@/navigation/researcherStack.types";
 import { useThemeStore } from '@/stores/themeStore';
 import AuthenticatedImage from '@/components/ui/AuthenticatedImage';
 import { useTaskDetails, useExperiments, useUpdateTaskStatus } from "@/api/queries";
+import ConfirmationModal from '@/components/ui/ConfirmationModal';
 
 type Props = NativeStackScreenProps<researcherStackParamList, "TaskDetails">;
 
@@ -52,6 +53,7 @@ export default function TaskDetailsScreen({ route, navigation }: Props) {
   const { data: task, isLoading: loading, error } = useTaskDetails(taskId);
   const { data: experimentsList } = useExperiments();
   const { mutate: updateStatus } = useUpdateTaskStatus();
+  const [showArchiveModal, setShowArchiveModal] = useState(false);
 
   // ── Loading state ──────────────────────────────────────────────────────────
   if (loading) {
@@ -85,11 +87,12 @@ export default function TaskDetailsScreen({ route, navigation }: Props) {
   const borderCol = isDark ? themeColors.border : '#BFDBFE';
 
   return (
-    <ScrollView
-      style={{ backgroundColor: themeColors.background }}
-      contentContainerStyle={[styles.container, { backgroundColor: themeColors.background }]}
-      showsVerticalScrollIndicator={false}
-    >
+    <>
+      <ScrollView
+        style={{ backgroundColor: themeColors.background }}
+        contentContainerStyle={[styles.container, { backgroundColor: themeColors.background }]}
+        showsVerticalScrollIndicator={false}
+      >
       {/* ── Back button ─────────────────────────────────────────────────────── */}
       <TouchableOpacity style={styles.backBtn} onPress={() => navigation.goBack()}>
         <Ionicons name="chevron-back" size={18} color="#3B82F6" />
@@ -163,43 +166,45 @@ export default function TaskDetailsScreen({ route, navigation }: Props) {
           </View>
 
           {/* ── Action buttons ───────────────────────────────────────────────── */}
-          <View style={styles.actionsRow}>
-            <TouchableOpacity
-              style={[styles.actionBtn, { backgroundColor: isDark ? '#1e3a5f' : '#DBEAFE', borderColor: '#3B82F6' }]}
-              onPress={() => navigation.navigate('EditTask', { taskId })}
-            >
-              <Ionicons name="create-outline" size={16} color="#3B82F6" />
-              <Text style={[styles.actionBtnText, { color: '#3B82F6' }]}>Edit</Text>
-            </TouchableOpacity>
-
-            <TouchableOpacity
-              style={[
-                styles.actionBtn,
-                {
-                  backgroundColor: isActive ? (isDark ? '#3d2e0a' : '#FEF3C7') : (isDark ? '#0d2e1c' : '#D1FAE5'),
-                  borderColor: isActive ? '#F59E0B' : '#10B981',
-                },
-              ]}
-              onPress={() => updateStatus({ taskId, action: isActive ? 'pause' : 'activate' })}
-            >
-              <Ionicons
-                name={isActive ? 'pause-circle-outline' : 'play-circle-outline'}
-                size={16}
-                color={isActive ? '#F59E0B' : '#10B981'}
-              />
-              <Text style={[styles.actionBtnText, { color: isActive ? '#F59E0B' : '#10B981' }]}>
-                {isActive ? 'Pause' : 'Resume'}
-              </Text>
-            </TouchableOpacity>
-
-            <TouchableOpacity
-              style={[styles.actionBtn, { backgroundColor: isDark ? '#2d1515' : '#FEE2E2', borderColor: '#EF4444' }]}
-              onPress={() => updateStatus({ taskId, action: 'archive' })}
-            >
-              <Ionicons name="archive-outline" size={16} color="#EF4444" />
-              <Text style={[styles.actionBtnText, { color: '#EF4444' }]}>Archive</Text>
-            </TouchableOpacity>
-          </View>
+          {task.status !== 'ARCHIVED' && (
+            <View style={styles.actionsRow}>
+              <TouchableOpacity
+                style={[styles.actionBtn, { backgroundColor: isDark ? '#1e3a5f' : '#DBEAFE', borderColor: '#3B82F6' }]}
+                onPress={() => navigation.navigate('EditTask', { taskId })}
+              >
+                <Ionicons name="create-outline" size={16} color="#3B82F6" />
+                <Text style={[styles.actionBtnText, { color: '#3B82F6' }]}>Edit</Text>
+              </TouchableOpacity>
+
+              <TouchableOpacity
+                style={[
+                  styles.actionBtn,
+                  {
+                    backgroundColor: isActive ? (isDark ? '#3d2e0a' : '#FEF3C7') : (isDark ? '#0d2e1c' : '#D1FAE5'),
+                    borderColor: isActive ? '#F59E0B' : '#10B981',
+                  },
+                ]}
+                onPress={() => updateStatus({ taskId, action: isActive ? 'pause' : 'activate' })}
+              >
+                <Ionicons
+                  name={isActive ? 'pause-circle-outline' : 'play-circle-outline'}
+                  size={16}
+                  color={isActive ? '#F59E0B' : '#10B981'}
+                />
+                <Text style={[styles.actionBtnText, { color: isActive ? '#F59E0B' : '#10B981' }]}>
+                  {isActive ? 'Pause' : 'Resume'}
+                </Text>
+              </TouchableOpacity>
+
+              <TouchableOpacity
+                style={[styles.actionBtn, { backgroundColor: isDark ? '#2d1515' : '#FEE2E2', borderColor: '#EF4444' }]}
+                onPress={() => setShowArchiveModal(true)}
+              >
+                <Ionicons name="archive-outline" size={16} color="#EF4444" />
+                <Text style={[styles.actionBtnText, { color: '#EF4444' }]}>Archive</Text>
+              </TouchableOpacity>
+            </View>
+          )}
         </View>
       </View>
 
@@ -293,7 +298,20 @@ export default function TaskDetailsScreen({ route, navigation }: Props) {
           ))}
         </>
       )}
-    </ScrollView>
+      </ScrollView>
+
+      <ConfirmationModal
+        visible={showArchiveModal}
+        title="Archive Task"
+        message="Are you sure you want to archive this task? Once archived, it cannot be returned to an active state."
+        confirmText="Archive"
+        onConfirm={() => {
+          updateStatus({ taskId, action: 'archive' });
+          setShowArchiveModal(false);
+        }}
+        onCancel={() => setShowArchiveModal(false)}
+      />
+    </>
   );
 }
 
diff --git a/frontend/app/screens/researcher/TasksManagementScreen.tsx b/frontend/app/screens/researcher/TasksManagementScreen.tsx
index 70ec050..afabb54 100644
--- a/frontend/app/screens/researcher/TasksManagementScreen.tsx
+++ b/frontend/app/screens/researcher/TasksManagementScreen.tsx
@@ -8,6 +8,7 @@ import { useAdminTasks, useUpdateTaskStatus } from '@/api/queries';
 import TaskCard from '@/components/researcher/TaskCard';
 import ScreenHeaderLayout from '@/components/layout/ScreenHeaderLayout';
 import { useThemeStore } from '@/stores/themeStore';
+import ConfirmationModal from '@/components/ui/ConfirmationModal';
 
 type StatusFilter = 'ALL' | 'ACTIVE' | 'PAUSED' | 'ARCHIVED' | 'PROCESSING';
 
@@ -35,6 +36,7 @@ export default function TasksManagementScreen({ navigation }: any) {
 
   const [searchQuery, setSearchQuery] = useState('');
   const [activeFilter, setActiveFilter] = useState<StatusFilter>('ALL');
+  const [taskToArchive, setTaskToArchive] = useState<number | null>(null);
 
   const filtered = tasks.filter((t: any) => {
     const matchesSearch = t.name.toLowerCase().includes(searchQuery.toLowerCase());
@@ -120,13 +122,27 @@ export default function TasksManagementScreen({ navigation }: any) {
                   updateStatus({ taskId: item.taskId, action: item.status === 'ACTIVE' ? 'pause' : 'activate' });
                 }}
                 onArchive={() => {
-                  updateStatus({ taskId: item.taskId, action: 'archive' });
+                  setTaskToArchive(item.taskId);
                 }}
               />
             )}
           />
         )}
       </View>
+
+      <ConfirmationModal
+        visible={taskToArchive !== null}
+        title="Archive Task"
+        message="Are you sure you want to archive this task? Once archived, it cannot be returned to an active state."
+        confirmText="Archive"
+        onConfirm={() => {
+          if (taskToArchive !== null) {
+            updateStatus({ taskId: taskToArchive, action: 'archive' });
+          }
+          setTaskToArchive(null);
+        }}
+        onCancel={() => setTaskToArchive(null)}
+      />
     </ScreenHeaderLayout>
   );
 }
diff --git a/frontend/app/screens/researcher/UsersManagementScreen.tsx b/frontend/app/screens/researcher/UsersManagementScreen.tsx
index 7bdd56a..ce2cccc 100644
--- a/frontend/app/screens/researcher/UsersManagementScreen.tsx
+++ b/frontend/app/screens/researcher/UsersManagementScreen.tsx
@@ -12,6 +12,7 @@ import {
     View,
     Alert,
 } from 'react-native';
+import { Ionicons } from '@expo/vector-icons';
 import useResponsive from '@/hooks/useResponsive';
 import { Colors } from '../../../constants/theme';
 import { API_ENDPOINTS } from '@/api/apiEndpoints';
@@ -36,6 +37,7 @@ interface User {
     // credibilityScore: composite 0–100 score from backend UserProfileResponse
     credibilityScore: number;
     active: boolean;
+    role?: string;
 }
 
 const SORT_ICONS: Record<SortOrder, string> = {
@@ -56,6 +58,17 @@ const SORT_LABELS: Record<SortOrder, string> = {
     desc: 'Credibility ↓',
 };
 
+const getAvatarConfig = (role?: string) => {
+    switch (role) {
+        case 'SUPER_ADMIN':
+            return { bg: '#8B5CF6', iconName: 'shield-checkmark' as const, isIonicon: true };
+        case 'RESEARCHER':
+            return { bg: '#3B82F6', iconName: 'flask' as const, isIonicon: true };
+        default:
+            return { bg: '#D8BFD8', isIonicon: false };
+    }
+};
+
 
 
 export default function UsersManagementScreen() {
@@ -142,13 +155,16 @@ export default function UsersManagementScreen() {
                         Credibility {SORT_ICONS[sortOrder]}
                     </Text>
                 </TouchableOpacity>
+                <Text style={[webStyles.headerCell, webStyles.roleCol, { color: themeColors.textSecondary }]}>Role</Text>
                 <Text style={[webStyles.headerCell, webStyles.statusCol, { color: themeColors.textSecondary }]}>Status</Text>
-                <Text style={[webStyles.headerCell, webStyles.actionCol, { color: themeColors.textSecondary }]}>Actions</Text>
+                <Text style={[webStyles.headerCell, webStyles.actionCol, { color: themeColors.textSecondary, textAlign: 'center' }]}>Actions</Text>
             </View>
 
             {/* Table Body */}
             <ScrollView style={webStyles.tableBody}>
-                {displayedUsers.map((item: User, index: number) => (
+                {displayedUsers.map((item: User, index: number) => {
+                    const avatarConfig = getAvatarConfig(item.role);
+                    return (
                     <View
                         key={item.username}
                         style={[
@@ -158,15 +174,26 @@ export default function UsersManagementScreen() {
                         ]}
                     >
                         <View style={[webStyles.cell, webStyles.avatarCol]}>
-                            <View style={webStyles.avatarWrapper}>
-                                <Image source={profileImg} style={webStyles.avatar} />
+                            <View style={[webStyles.avatarWrapper, { backgroundColor: avatarConfig.bg }]}>
+                                {avatarConfig.isIonicon ? (
+                                    <Ionicons name={avatarConfig.iconName} size={18} color="white" />
+                                ) : (
+                                    <Image source={profileImg} style={webStyles.avatar} />
+                                )}
                             </View>
                         </View>
                         <View style={[webStyles.cell, webStyles.usernameCol]}>
                             <Text style={[webStyles.usernameText, { color: themeColors.text }]}>{item.username}</Text>
                         </View>
                         <View style={[webStyles.cell, webStyles.scoreCol]}>
-                            <Text style={[webStyles.scoreText, { color: themeColors.text }]}>{item.credibilityScore ?? '—'}</Text>
+                            <Text style={[webStyles.scoreText, { color: themeColors.text }]}>
+                                {item.credibilityScore != null ? Math.round(item.credibilityScore) : '—'}
+                            </Text>
+                        </View>
+                        <View style={[webStyles.cell, webStyles.roleCol]}>
+                            <Text style={[webStyles.roleText, { color: themeColors.textSecondary }]}>
+                                {item.role ?? 'USER'}
+                            </Text>
                         </View>
                         <View style={[webStyles.cell, webStyles.statusCol]}>
                             <View style={[webStyles.statusBadge, { backgroundColor: item.active ? '#e6f7ff' : '#fff1f0' }]}>
@@ -190,28 +217,42 @@ export default function UsersManagementScreen() {
                             )}
                         </View>
                     </View>
-                ))}
+                    );
+                })}
             </ScrollView>
         </View>
     );
 
     // ─── Mobile: card grid layout ─────────────────────────────────────────────
-    const renderMobileCard = ({ item }: { item: User }) => (
+    const renderMobileCard = ({ item }: { item: User }) => {
+        const avatarConfig = getAvatarConfig(item.role);
+        return (
         <View style={[mobileStyles.card, { backgroundColor: themeColors.card, borderColor: themeColors.border }]}>
             {/* Avatar */}
-            <View style={mobileStyles.avatarContainer}>
-                <Image source={profileImg} style={mobileStyles.avatar} />
+            <View style={[mobileStyles.avatarContainer, { backgroundColor: avatarConfig.bg }]}>
+                {avatarConfig.isIonicon ? (
+                    <Ionicons name={avatarConfig.iconName} size={24} color="white" />
+                ) : (
+                    <Image source={profileImg} style={mobileStyles.avatar} />
+                )}
             </View>
 
             {/* Username */}
             <Text style={[mobileStyles.username, { color: themeColors.text }]} numberOfLines={1}>
                 {item.username}
             </Text>
+            
+            {/* Role */}
+            <Text style={[mobileStyles.roleLabel, { color: themeColors.textSecondary }]}>
+                {item.role ?? 'USER'}
+            </Text>
 
             {/* Credibility row */}
             <View style={mobileStyles.scoreRow}>
                 <Text style={[mobileStyles.scoreLabel, { color: themeColors.textSecondary }]}>Credibility </Text>
-                <Text style={[mobileStyles.scoreValue, { color: themeColors.text }]}>{item.credibilityScore ?? '—'}</Text>
+                <Text style={[mobileStyles.scoreValue, { color: themeColors.text }]}>
+                    {item.credibilityScore != null ? Math.round(item.credibilityScore) : '—'}
+                </Text>
             </View>
 
             {/* Status badge */}
@@ -231,7 +272,8 @@ export default function UsersManagementScreen() {
                 </TouchableOpacity>
             )}
         </View>
-    );
+        );
+    };
 
     return (
         <ScreenHeaderLayout
@@ -367,11 +409,16 @@ const mobileStyles = StyleSheet.create({
     username: {
         fontSize: 13,
         fontWeight: '700',
-        marginBottom: 6,
+        marginBottom: 2,
         textAlign: 'center',
         // Prevent overflow
         maxWidth: '100%',
     },
+    roleLabel: {
+        fontSize: 11,
+        marginBottom: 6,
+        textTransform: 'capitalize',
+    },
     scoreRow: {
         flexDirection: 'row',
         alignItems: 'center',
@@ -455,16 +502,18 @@ const webStyles = StyleSheet.create({
     avatarCol: { width: 60, alignItems: 'center' },
     usernameCol: { flex: 2, paddingLeft: 16 },
     scoreCol: { flex: 1 },
-    statusCol: { flex: 1 },
-    actionCol: { flex: 1.5, alignItems: 'flex-end' },
+    roleCol: { flex: 1 },
+    statusCol: { flex: 1, alignItems: 'flex-start' },
+    actionCol: { flex: 1.5, alignItems: 'center' },
 
     avatarWrapper: { width: 36, height: 36, borderRadius: 18, backgroundColor: '#D8BFD8', justifyContent: 'center', alignItems: 'center' },
     avatar: { width: 20, height: 20, tintColor: 'white' },
 
     usernameText: { fontSize: 15, fontWeight: '600' },
     scoreText: { fontSize: 15 },
+    roleText: { fontSize: 14, textTransform: 'capitalize' },
 
-    statusBadge: { paddingHorizontal: 12, paddingVertical: 4, borderRadius: 12 },
+    statusBadge: { paddingHorizontal: 12, paddingVertical: 4, borderRadius: 12, alignSelf: 'flex-start' },
     statusText: { fontSize: 12, fontWeight: 'bold' },
 
     actionButton: { paddingVertical: 8, paddingHorizontal: 16, borderRadius: 6 },
diff --git a/frontend/app/screens/shared/MaintenanceScreen.tsx b/frontend/app/screens/shared/MaintenanceScreen.tsx
index 28a446f..bb2a555 100644
--- a/frontend/app/screens/shared/MaintenanceScreen.tsx
+++ b/frontend/app/screens/shared/MaintenanceScreen.tsx
@@ -1,9 +1,45 @@
-import React from 'react';
-import { View, Text, StyleSheet, ActivityIndicator, TouchableOpacity, Linking, SafeAreaView } from 'react-native';
+import React, { useState, useEffect } from 'react';
+import { View, Text, StyleSheet, ActivityIndicator, TouchableOpacity, Linking, SafeAreaView, Platform } from 'react-native';
 import { Image } from 'expo-image';
 import { theme } from '@/theme/theme';
+import Animated, { FadeIn, FadeInDown, SlideInDown } from 'react-native-reanimated';
+import { useAppStateStore } from '@/stores/appStateStore';
+import { API_ENDPOINTS } from '@/api/apiEndpoints';
+import { backendUrl } from '@/api/apiFetch';
+
+const STATUS_MESSAGES = [
+  "Diagnosing system health...",
+  "Restoring database connections...",
+  "Re-establishing secure links...",
+  "Synchronizing data pipelines...",
+  "Finalizing system checks..."
+];
 
 export function MaintenanceScreen() {
+  const [statusIndex, setStatusIndex] = useState(0);
+  const setMaintenanceMode = useAppStateStore((state) => state.setMaintenanceMode);
+
+  useEffect(() => {
+    const statusInterval = setInterval(() => {
+      setStatusIndex((prev) => (prev + 1) % STATUS_MESSAGES.length);
+    }, 4000);
+    return () => clearInterval(statusInterval);
+  }, []);
+
+  useEffect(() => {
+    const healthInterval = setInterval(async () => {
+      try {
+        const res = await fetch(backendUrl + API_ENDPOINTS.SYSTEM.HEALTH, { method: 'GET' });
+        if (res.ok) {
+          setMaintenanceMode(false);
+        }
+      } catch (e) {
+        // Backend is still down
+      }
+    }, 10000);
+    return () => clearInterval(healthInterval);
+  }, [setMaintenanceMode]);
+
   const handleContactSupport = () => {
     Linking.openURL('mailto:swipelab.developers@gmail.com?subject=SwipeLab%20-%20Server%20is%20down');
   };
@@ -11,27 +47,41 @@ export function MaintenanceScreen() {
   return (
     <SafeAreaView style={styles.container}>
       <View style={styles.content}>
-        <Image 
-          source={require('../../../assets/images/swipelab.gif')} 
-          style={styles.logo} 
-          contentFit="contain"
-        />
-        <Image 
-          source={require('../../../assets/images/maintenance.gif')} 
-          style={styles.mainImage} 
-          contentFit="contain"
-        />
-        <Text style={styles.title}>We&apos;ll be right back!</Text>
-        <Text style={styles.message}>
+        <Animated.View entering={FadeInDown.duration(800).delay(100)} pointerEvents="none">
+          <Image 
+            source={Platform.OS === 'web' ? { uri: '/swipelab.gif' } : require('../../../assets/images/swipelab.gif')} 
+            style={styles.logo} 
+            contentFit="contain"
+          />
+        </Animated.View>
+
+        <Animated.View entering={FadeInDown.duration(800).delay(200)} pointerEvents="none">
+          <Image 
+            source={Platform.OS === 'web' ? { uri: '/maintenance.gif' } : require('../../../assets/images/maintenance.gif')} 
+            style={styles.mainImage} 
+            contentFit="contain"
+          />
+        </Animated.View>
+
+        <Animated.Text entering={FadeInDown.duration(800).delay(300)} style={styles.title}>
+          We'll be right back!
+        </Animated.Text>
+        
+        <Animated.Text entering={FadeInDown.duration(800).delay(400)} style={styles.message}>
           SwipeLab is currently undergoing maintenance. 
-          We&apos;re working hard to make things better for you.
-        </Text>
+          We're working hard to make things better for you.
+        </Animated.Text>
         
-        <ActivityIndicator size="large" color="#ffffff" style={styles.loader} />
+        <Animated.View entering={FadeIn.duration(800).delay(500)} style={styles.statusContainer}>
+          <ActivityIndicator size="small" color={theme.colors.primary} style={styles.loader} />
+          <Text style={styles.statusText}>{STATUS_MESSAGES[statusIndex]}</Text>
+        </Animated.View>
         
-        <TouchableOpacity style={styles.contactButton} onPress={handleContactSupport}>
-          <Text style={styles.contactButtonText}>Contact Support</Text>
-        </TouchableOpacity>
+        <Animated.View entering={SlideInDown.duration(800).delay(700)}>
+          <TouchableOpacity style={styles.contactButton} onPress={handleContactSupport}>
+            <Text style={styles.contactButtonText}>Contact Support</Text>
+          </TouchableOpacity>
+        </Animated.View>
       </View>
     </SafeAreaView>
   );
@@ -40,8 +90,8 @@ export function MaintenanceScreen() {
 const styles = StyleSheet.create({
   container: {
     ...StyleSheet.absoluteFillObject,
-    backgroundColor: theme.colors.primary,
-    zIndex: 9999, // Ensure it overlays everything
+    backgroundColor: '#ffffff',
+    zIndex: 9999,
   },
   content: {
     flex: 1,
@@ -62,27 +112,39 @@ const styles = StyleSheet.create({
   title: {
     fontSize: theme.typography.sizes.xl,
     fontWeight: 'bold',
-    color: '#ffffff',
+    color: theme.colors.primary,
     marginBottom: theme.spacing.md,
     textAlign: 'center',
   },
   message: {
     fontSize: theme.typography.sizes.md,
-    color: 'rgba(255, 255, 255, 0.8)',
+    color: '#666666',
     textAlign: 'center',
     lineHeight: 24,
-    marginBottom: theme.spacing.xl,
+    marginBottom: theme.spacing.lg,
   },
-  loader: {
+  statusContainer: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    backgroundColor: 'rgba(0,0,0,0.03)',
+    paddingVertical: theme.spacing.sm,
+    paddingHorizontal: theme.spacing.lg,
+    borderRadius: theme.borderRadius.round,
     marginBottom: theme.spacing.xxl,
   },
+  loader: {
+    marginRight: theme.spacing.sm,
+  },
+  statusText: {
+    color: theme.colors.primary,
+    fontSize: theme.typography.sizes.sm,
+    fontWeight: '500',
+  },
   contactButton: {
-    backgroundColor: 'rgba(255, 255, 255, 0.2)',
+    backgroundColor: theme.colors.primary,
     paddingVertical: theme.spacing.md,
     paddingHorizontal: theme.spacing.xl,
     borderRadius: theme.borderRadius.round,
-    borderWidth: 1,
-    borderColor: 'rgba(255, 255, 255, 0.5)',
   },
   contactButtonText: {
     color: '#ffffff',
diff --git a/frontend/app/screens/shared/ProfileScreen.tsx b/frontend/app/screens/shared/ProfileScreen.tsx
index 15a3d6f..727c62c 100644
--- a/frontend/app/screens/shared/ProfileScreen.tsx
+++ b/frontend/app/screens/shared/ProfileScreen.tsx
@@ -157,16 +157,22 @@ export default function ProfileScreen() {
                 <View style={styles.section}>
                     <Text style={[styles.sectionTitle, { color: themeColors.text }]}>Badges</Text>
                     <View style={styles.badgesContainer}>
-                        {myBadges?.map((badge: any, index: number) => (
-                            <View key={index} style={[styles.badge, { backgroundColor: themeColors.background, borderColor: themeColors.border, alignItems: 'center' }]}>
-                                {badge.iconUrl && typeof badge.iconUrl === 'string' && badge.iconUrl.startsWith('http') ? (
-                                    <Image source={{ uri: badge.iconUrl }} style={styles.badgeImage} />
-                                ) : (
-                                    <Image source={getBadgeIcon(badge.title)} style={styles.badgeImage} />
-                                )}
-                                <Text style={[styles.badgeText, { fontSize: 14, color: themeColors.text, textAlign: 'center' }]}>{badge.title}</Text>
-                            </View>
-                        ))}
+                        {myBadges && myBadges.length > 0 ? (
+                            myBadges.map((badge: any, index: number) => (
+                                <View key={index} style={[styles.badge, { backgroundColor: themeColors.background, borderColor: themeColors.border, alignItems: 'center' }]}>
+                                    {badge.iconUrl && typeof badge.iconUrl === 'string' && badge.iconUrl.startsWith('http') ? (
+                                        <Image source={{ uri: badge.iconUrl }} style={styles.badgeImage} />
+                                    ) : (
+                                        <Image source={getBadgeIcon(badge.title)} style={styles.badgeImage} />
+                                    )}
+                                    <Text style={[styles.badgeText, { fontSize: 14, color: themeColors.text, textAlign: 'center' }]}>{badge.title}</Text>
+                                </View>
+                            ))
+                        ) : (
+                            <Text style={{ color: themeColors.textSecondary, fontStyle: 'italic', marginTop: 8 }}>
+                                No badges earned yet. Keep classifying!
+                            </Text>
+                        )}
                     </View>
                 </View>
 
diff --git a/frontend/app/screens/shared/SettingsScreen.tsx b/frontend/app/screens/shared/SettingsScreen.tsx
index 03b864e..0c80276 100644
--- a/frontend/app/screens/shared/SettingsScreen.tsx
+++ b/frontend/app/screens/shared/SettingsScreen.tsx
@@ -1,5 +1,5 @@
 import React, { useState } from 'react';
-import { View, Text, StyleSheet, ScrollView, TouchableOpacity, Switch } from 'react-native';
+import { View, Text, StyleSheet, ScrollView, TouchableOpacity, Switch, Modal, Linking, Platform } from 'react-native';
 import { useNavigation } from '@react-navigation/native';
 import { Ionicons } from '@expo/vector-icons';
 import ScreenHeaderLayout from '@/components/layout/ScreenHeaderLayout/ScreenHeaderLayout';
@@ -7,10 +7,10 @@ import { useAuthStore } from '@/stores/authStore';
 import { useThemeStore } from '@/stores/themeStore';
 
 export default function SettingsScreen() {
-  const { logout } = useAuthStore();
-  const isSuperAdmin = useAuthStore((state) => state.isSuperAdmin);
+  const { logout, isSuperAdmin, role } = useAuthStore();
   const { theme, toggleTheme } = useThemeStore();
   const [notifications, setNotifications] = useState(true);
+  const [isAboutVisible, setIsAboutVisible] = useState(false);
   const navigation = useNavigation<any>();
 
   const isDarkMode = theme === 'dark';
@@ -39,6 +39,18 @@ export default function SettingsScreen() {
     },
   };
 
+  const handleHelpCenter = () => {
+    const isResearchMode = role === 'RESEARCHER' || isSuperAdmin;
+    const url = isResearchMode 
+        ? 'https://swipelab-project.netlify.app/researcher-manual' 
+        : 'https://swipelab-project.netlify.app/user-manual';
+    Linking.openURL(url).catch((err) => console.error("Couldn't load page", err));
+  };
+
+  const handleAbout = () => {
+    setIsAboutVisible(true);
+  };
+
   return (
     <ScreenHeaderLayout
       leftIcon={require('../../../assets/images/settings.png')}
@@ -120,7 +132,7 @@ export default function SettingsScreen() {
           <View style={styles.section}>
             <Text style={[styles.sectionTitle, dynamicStyles.sectionTitle]}>Support</Text>
 
-            <TouchableOpacity style={[styles.settingRow, dynamicStyles.settingRow]}>
+            <TouchableOpacity style={[styles.settingRow, dynamicStyles.settingRow]} onPress={handleHelpCenter}>
               <View style={styles.settingLeft}>
                 <Ionicons name="help-circle-outline" size={24} color={dynamicStyles.iconColor} />
                 <Text style={[styles.settingLabel, dynamicStyles.settingLabel]}>Help Center</Text>
@@ -128,7 +140,7 @@ export default function SettingsScreen() {
               <Ionicons name="open-outline" size={20} color={dynamicStyles.chevronColor} />
             </TouchableOpacity>
 
-            <TouchableOpacity style={[styles.settingRow, dynamicStyles.settingRow]}>
+            <TouchableOpacity style={[styles.settingRow, dynamicStyles.settingRow]} onPress={handleAbout}>
               <View style={styles.settingLeft}>
                 <Ionicons name="information-circle-outline" size={24} color={dynamicStyles.iconColor} />
                 <Text style={[styles.settingLabel, dynamicStyles.settingLabel]}>About</Text>
@@ -146,6 +158,32 @@ export default function SettingsScreen() {
           <Text style={[styles.versionText, dynamicStyles.versionText]}>SwipeLab v1.0.0-alpha</Text>
         </ScrollView>
       </View>
+
+      {/* Custom About Modal */}
+      <Modal
+        visible={isAboutVisible}
+        transparent={true}
+        animationType="fade"
+        onRequestClose={() => setIsAboutVisible(false)}
+      >
+        <View style={styles.modalOverlay}>
+          <View style={[styles.modalContent, { backgroundColor: isDarkMode ? '#2d2d44' : '#fff' }]}>
+            <Text style={[styles.modalTitle, { color: isDarkMode ? '#fff' : '#333' }]}>About SwipeLab</Text>
+            <Text style={[styles.modalText, { color: isDarkMode ? '#d1d5db' : '#666' }]}>
+              SwipeLab v1.0.0-alpha{'\n\n'}
+              A platform for crowdsourced biological classifications.{'\n'}
+              Developed for research purposes.
+            </Text>
+            
+            <TouchableOpacity 
+              style={styles.closeButton} 
+              onPress={() => setIsAboutVisible(false)}
+            >
+              <Text style={styles.closeButtonText}>Close</Text>
+            </TouchableOpacity>
+          </View>
+        </View>
+      </Modal>
     </ScreenHeaderLayout >
   );
 }
@@ -219,4 +257,48 @@ const styles = StyleSheet.create({
     marginTop: 24,
     fontSize: 12,
   },
+  modalOverlay: {
+    flex: 1,
+    backgroundColor: 'rgba(0,0,0,0.5)',
+    justifyContent: 'center',
+    alignItems: 'center',
+    padding: 20,
+  },
+  modalContent: {
+    width: '100%',
+    maxWidth: 350,
+    borderRadius: 16,
+    padding: 24,
+    alignItems: 'center',
+    shadowColor: '#000',
+    shadowOffset: { width: 0, height: 4 },
+    shadowOpacity: 0.2,
+    shadowRadius: 8,
+    elevation: 5,
+  },
+  modalTitle: {
+    fontSize: 20,
+    fontWeight: 'bold',
+    marginBottom: 16,
+    textAlign: 'center',
+  },
+  modalText: {
+    fontSize: 15,
+    textAlign: 'center',
+    lineHeight: 22,
+    marginBottom: 24,
+  },
+  closeButton: {
+    backgroundColor: '#007AFF',
+    paddingVertical: 10,
+    paddingHorizontal: 24,
+    borderRadius: 8,
+    width: '100%',
+    alignItems: 'center',
+  },
+  closeButtonText: {
+    color: '#fff',
+    fontSize: 16,
+    fontWeight: 'bold',
+  },
 });
\ No newline at end of file
diff --git a/frontend/app/screens/user/LeaderboardScreen.tsx b/frontend/app/screens/user/LeaderboardScreen.tsx
index 79fecb9..9e75bc2 100644
--- a/frontend/app/screens/user/LeaderboardScreen.tsx
+++ b/frontend/app/screens/user/LeaderboardScreen.tsx
@@ -112,7 +112,7 @@ function RankBadge({ themeColors, isDark }: { themeColors: any; isDark: boolean
     const color = RANK_COLORS[rankData.tier] ?? '#9ca3af';
     const nextLabel = rankData.nextTierAt === -1
         ? 'MAX'
-        : `${rankData.yesTagCount} / ${rankData.nextTierAt} tags`;
+        : `${rankData.yesTagCount} / ${rankData.nextTierAt} Yes labels`;
 
     return (
         <View style={[rankStyles.container, { backgroundColor: isDark ? themeColors.card : '#fff' }]}>
diff --git a/frontend/app/screens/user/StatsScreen.tsx b/frontend/app/screens/user/StatsScreen.tsx
index 0880c5a..78e2aa8 100644
--- a/frontend/app/screens/user/StatsScreen.tsx
+++ b/frontend/app/screens/user/StatsScreen.tsx
@@ -57,6 +57,7 @@ interface UserInfoData {
     score: number;
     badge: string | null;
     currentStreak: number;
+    longestStreak: number;
 }
 
 interface StatsData {
@@ -147,9 +148,9 @@ export default function StatsScreen() {
 
                 {/* User Profile Summary */}
                 <View style={styles.grid}>
-                    <SummaryCard title="Global Rank" value={`#${data.summary?.summary?.rank?.allTime ?? '-'}`} subtext="Top 1%" icon="🌍" />
+                    <SummaryCard title="Global Rank" value={`#${data.summary?.summary?.rank?.allTime ?? '-'}`} subtext={`Top ${Math.max(0, 100 - (data.vsUsers?.percentile ?? 0)).toFixed(0)}%`} icon="🌍" />
                     <SummaryCard title="Score" value={data.userInfo?.score?.toLocaleString() ?? '0'} icon="🌟" />
-                    <SummaryCard title="Tasks Done" value={data.summary?.summary?.totalClassifications ?? 0} icon="✅" />
+                    <SummaryCard title="Images Labeled" value={data.summary?.summary?.totalClassifications ?? 0} icon="✅" />
                     <SummaryCard title="Accuracy" value={`${((data.summary?.summary?.accuracy ?? 0) * 100).toFixed(1)}%`} subtext="Overall" icon="🎯" />
                 </View>
 
@@ -158,7 +159,7 @@ export default function StatsScreen() {
                     <Text style={[styles.sectionTitle, { color: themeColors.text }]}>🔥 Streak</Text>
                     <View style={[styles.streakContainer, { backgroundColor: themeColors.card }]}>
                         <Text style={[styles.streakText, { color: themeColors.text }]}>Current: <Text style={styles.streakBold}>{data.userInfo?.currentStreak ?? 0} days</Text></Text>
-                        <Text style={[styles.streakText, { color: themeColors.text }]}>Longest: <Text style={styles.streakBold}>{data.summary?.summary?.longestStreak ?? 0} days</Text></Text>
+                        <Text style={[styles.streakText, { color: themeColors.text }]}>Longest: <Text style={styles.streakBold}>{data.userInfo?.longestStreak ?? 0} days</Text></Text>
                     </View>
                 </View>
 
diff --git a/frontend/app/screens/user/SwipeScreen.tsx b/frontend/app/screens/user/SwipeScreen.tsx
index 57bc4a3..c286b60 100644
--- a/frontend/app/screens/user/SwipeScreen.tsx
+++ b/frontend/app/screens/user/SwipeScreen.tsx
@@ -33,9 +33,10 @@ const ACCENT = '#4B7BE5';
 export default function SwipeScreen() {
   const navigation = useNavigation<any>();
   const [showReference, setShowReference] = useState(false);
-  const { dataBatch, currentIndex, activeTaskId, setActiveTaskId, setBatch, nextCard, clearBatch } =
+  const { dataBatch, currentIndex, activeTaskId, setActiveTaskId, setBatch, appendBatch, nextCard, clearBatch } =
     useSwipeStore();
   const [loading, setLoading] = useState(false);
+  const [isFetchingNextBatch, setIsFetchingNextBatch] = useState(false);
   const [error, setError] = useState<string | null>(null);
   const [activeWarning, setActiveWarning] = useState<ClassificationWarning | null>(null);
 
@@ -96,9 +97,38 @@ export default function SwipeScreen() {
     }
   };
 
+  const fetchNextBatchInBackground = async () => {
+    setIsFetchingNextBatch(true);
+    try {
+      const res = await apiFetch(
+        API_ENDPOINTS.CLASSIFICATIONS.NEXT_BATCH(activeTaskId as string | number, 5),
+        { method: 'GET' }
+      );
+      if (res.ok) {
+        const json = await res.json();
+        const newImages = json.images || [];
+        if (newImages.length > 0) {
+          appendBatch(newImages);
+          queryClient.setQueryData(QUERY_KEYS.swipeBatch(activeTaskId as string | number), (old: any) => {
+             return { images: [...(old?.images || []), ...newImages] };
+          });
+        }
+      }
+    } catch (e: any) {
+      console.error('Background batch fetch failed', e);
+    } finally {
+      setIsFetchingNextBatch(false);
+    }
+  };
+
   const handleSwipe = (direction: SwipeDirection) => {
     const currentImage = dataBatch[currentIndex];
 
+    const cardsLeft = dataBatch.length - (currentIndex + 1);
+    if (cardsLeft <= 3 && !loading && !isFetchingNextBatch) {
+      fetchNextBatchInBackground();
+    }
+
     // Immediately advance UI to the next card
     if (currentIndex + 1 < dataBatch.length) {
       nextCard();
diff --git a/frontend/app/stores/downloadStore.ts b/frontend/app/stores/downloadStore.ts
new file mode 100644
index 0000000..54e1824
--- /dev/null
+++ b/frontend/app/stores/downloadStore.ts
@@ -0,0 +1,30 @@
+import { create } from 'zustand';
+
+export interface DownloadTask {
+  taskId: number;
+  taskName: string;
+}
+
+interface DownloadState {
+  activeExports: DownloadTask[];
+  addTasks: (tasks: DownloadTask[]) => void;
+  removeTasks: (taskIds: number[]) => void;
+}
+
+export const useDownloadStore = create<DownloadState>((set) => ({
+  activeExports: [],
+  addTasks: (tasks) =>
+    set((state) => {
+      // Prevent duplicates if a user tries to download the same task again while it's in progress
+      const existingIds = new Set(state.activeExports.map((t) => t.taskId));
+      const newTasks = tasks.filter((t) => !existingIds.has(t.taskId));
+      return { activeExports: [...state.activeExports, ...newTasks] };
+    }),
+  removeTasks: (taskIds) =>
+    set((state) => {
+      const idsToRemove = new Set(taskIds);
+      return {
+        activeExports: state.activeExports.filter((t) => !idsToRemove.has(t.taskId)),
+      };
+    }),
+}));
diff --git a/frontend/app/stores/swipeStore.ts b/frontend/app/stores/swipeStore.ts
index e3aec6d..d0422a2 100644
--- a/frontend/app/stores/swipeStore.ts
+++ b/frontend/app/stores/swipeStore.ts
@@ -7,6 +7,7 @@ interface SwipeStore {
   activeTaskId: string | number | null;
 
   setBatch: (items: any[]) => void;
+  appendBatch: (items: any[]) => void;
   nextCard: () => void;
   clearBatch: () => void;
   getCurrentImage: () => any | null;
@@ -22,6 +23,10 @@ export const useSwipeStore = create<SwipeStore>((set, get) => ({
     set({ dataBatch: items, currentIndex: 0 });
   },
 
+  appendBatch: (items: any[]) => {
+    set((state) => ({ dataBatch: [...state.dataBatch, ...items] }));
+  },
+
   nextCard: () => {
     set((state) => ({ currentIndex: state.currentIndex + 1 }));
   },
diff --git a/frontend/public/maintenance.gif b/frontend/public/maintenance.gif
new file mode 100644
index 0000000..0ec9864
Binary files /dev/null and b/frontend/public/maintenance.gif differ
diff --git a/frontend/public/swipelab.gif b/frontend/public/swipelab.gif
new file mode 100644
index 0000000..22fda29
Binary files /dev/null and b/frontend/public/swipelab.gif differ
diff --git a/frontend/tests/e2e/helpers.ts b/frontend/tests/e2e/helpers.ts
index 4bcbea7..8673630 100644
--- a/frontend/tests/e2e/helpers.ts
+++ b/frontend/tests/e2e/helpers.ts
@@ -35,7 +35,7 @@ export async function gotoLogin(page: Page): Promise<void> {
     try { window.localStorage.clear(); } catch {}
   });
   await page.reload();
-  await page.waitForLoadState('networkidle');
+  await page.waitForLoadState('domcontentloaded');
   await expect(page.locator('text=Welcome to SwipeLab')).toBeVisible({ timeout: 20000 });
 }
 
diff --git a/frontend/tests/e2e/researcher/pause-archive-task.spec.ts b/frontend/tests/e2e/researcher/pause-archive-task.spec.ts
index 5005a87..2b3c2f5 100644
--- a/frontend/tests/e2e/researcher/pause-archive-task.spec.ts
+++ b/frontend/tests/e2e/researcher/pause-archive-task.spec.ts
@@ -15,7 +15,7 @@ const ARCHIVE_TASK = 'E2E Archive Target';
 async function loginAsResearcher(page: Page): Promise<void> {
     await test.step('Login as researcher', async () => {
         await page.goto(BASE_URL);
-        await page.waitForLoadState('networkidle');
+        await page.waitForLoadState('domcontentloaded');
         await page.waitForTimeout(1500);
 
         await expect(page.locator('text=Welcome to SwipeLab')).toBeVisible({ timeout: 15000 });
@@ -95,6 +95,10 @@ test.describe('[E2E] R8 Pause / Archive Task', () => {
             // Click the Archive button
             await expect(page.getByText('Archive', { exact: true }).last()).toBeVisible();
             await page.getByText('Archive', { exact: true }).last().click();
+            
+            // Confirm the archive action in the modal
+            await expect(page.getByText('Are you sure you want to archive', { exact: false }).last()).toBeVisible();
+            await page.getByText('Archive', { exact: true }).last().click();
         });
 
         await test.step('Verify archive status', async () => {