diff --git a/.clang-tidy b/.clang-tidy
index 09c386ce0..3b50a351b 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -73,6 +73,12 @@ CheckOptions:
     value: lower_case
   - key: readability-identifier-naming.ConstantCase
     value: UPPER_CASE
+  - key: readability-identifier-naming.LocalConstantCase
+    value: lower_case
+  - key: readability-identifier-naming.LocalConstantPointerCase
+    value: lower_case
+  - key: readability-identifier-naming.StaticConstantCase
+    value: UPPER_CASE
   - key: readability-identifier-naming.NamespaceCase
     value: lower_case
   - key: readability-identifier-naming.EnumCase
@@ -83,6 +89,8 @@ CheckOptions:
     value: lower_case
   - key: readability-identifier-naming.PrivateMemberSuffix
     value: '_'
+  - key: readability-identifier-naming.ProtectedMemberSuffix
+    value: '_'
   - key: readability-identifier-naming.EnumConstantCase
     value: UPPER_CASE
 ...
diff --git a/src/e2e/e2e_crc.cpp b/src/e2e/e2e_crc.cpp
index fe60b33c3..06e8f0cac 100644
--- a/src/e2e/e2e_crc.cpp
+++ b/src/e2e/e2e_crc.cpp
@@ -39,7 +39,7 @@ uint8_t calculate_crc8_sae_j1850(const std::vector<uint8_t>& data) {
     for (uint8_t byte : data) {
         crc ^= byte;
         for (int i = 0; i < 8; ++i) {
-            if (crc & 0x80) {
+            if ((crc & 0x80) != 0) {
                 crc = (crc << 1) ^ SAE_J1850_POLY;
             } else {
                 crc <<= 1;
@@ -60,7 +60,7 @@ uint16_t calculate_crc16_itu_x25(const std::vector<uint8_t>& data) {
     for (uint8_t byte : data) {
         crc ^= (static_cast<uint16_t>(byte) << 8);
         for (int i = 0; i < 8; ++i) {
-            if (crc & 0x8000) {
+            if ((crc & 0x8000) != 0) {
                 crc = (crc << 1) ^ ITU_X25_POLY;
             } else {
                 crc <<= 1;
diff --git a/src/e2e/e2e_profile_registry.cpp b/src/e2e/e2e_profile_registry.cpp
index 25978488b..bcabc8a7b 100644
--- a/src/e2e/e2e_profile_registry.cpp
+++ b/src/e2e/e2e_profile_registry.cpp
@@ -37,8 +37,8 @@ bool E2EProfileRegistry::register_profile(E2EProfilePtr profile) {
 
     platform::ScopedLock const lock(mutex_);
 
-    uint32_t profile_id = profile->get_profile_id();
-    std::string profile_name = profile->get_profile_name();
+    uint32_t const profile_id = profile->get_profile_id();
+    std::string const profile_name = profile->get_profile_name();
 
     // Check if profile ID already exists
     if (profiles_by_id_.find(profile_id) != profiles_by_id_.end()) {
@@ -51,7 +51,7 @@ bool E2EProfileRegistry::register_profile(E2EProfilePtr profile) {
     }
 
     // Register profile
-    E2EProfile* raw_ptr = profile.get();
+    E2EProfile* const raw_ptr = profile.get();
     profiles_by_id_[profile_id] = std::move(profile);
     profiles_by_name_[profile_name] = raw_ptr;
 
@@ -93,7 +93,7 @@ bool E2EProfileRegistry::unregister_profile(uint32_t profile_id) {
     }
 
     // Remove from name map
-    std::string profile_name = it->second->get_profile_name();
+    std::string const profile_name = it->second->get_profile_name();
     profiles_by_name_.erase(profile_name);
 
     // Remove from ID map
diff --git a/src/e2e/e2e_protection.cpp b/src/e2e/e2e_protection.cpp
index 642b4687c..fa031c83a 100644
--- a/src/e2e/e2e_protection.cpp
+++ b/src/e2e/e2e_protection.cpp
@@ -32,16 +32,16 @@ Result E2EProtection::protect(Message& message, const E2EConfig& config) {
     E2EProfile* profile = registry.get_profile(config.profile_id);
 
     // If profile not found by ID, try by name
-    if (!profile) {
+    if (profile == nullptr) {
         profile = registry.get_profile(config.profile_name);
     }
 
     // If still not found, use default profile
-    if (!profile) {
+    if (profile == nullptr) {
         profile = registry.get_default_profile();
     }
 
-    if (!profile) {
+    if (profile == nullptr) {
         return Result::NOT_INITIALIZED;  // Basic profile not initialized
     }
 
@@ -62,16 +62,16 @@ Result E2EProtection::validate(const Message& message, const E2EConfig& config)
     E2EProfile* profile = registry.get_profile(config.profile_id);
 
     // If profile not found by ID, try by name
-    if (!profile) {
+    if (profile == nullptr) {
         profile = registry.get_profile(config.profile_name);
     }
 
     // If still not found, use default profile
-    if (!profile) {
+    if (profile == nullptr) {
         profile = registry.get_default_profile();
     }
 
-    if (!profile) {
+    if (profile == nullptr) {
         return Result::NOT_INITIALIZED;  // Basic profile not initialized
     }
 
diff --git a/src/events/event_publisher.cpp b/src/events/event_publisher.cpp
index 4a5fc1c3b..974d116ea 100644
--- a/src/events/event_publisher.cpp
+++ b/src/events/event_publisher.cpp
@@ -87,7 +87,7 @@ class EventPublisherImpl : public transport::ITransportListener {
         platform::ScopedLock const events_lock(events_mutex_);
 
         // Check if already registered
-        bool already_exists = registered_events_.count(config.event_id) > 0;
+        bool const already_exists = registered_events_.count(config.event_id) > 0;
         if (!already_exists) {
             registered_events_[config.event_id] = config;
         }
@@ -277,7 +277,7 @@ class EventPublisherImpl : public transport::ITransportListener {
                 if (config.notification_type == NotificationType::PERIODIC &&
                     config.cycle_time.count() > 0) {
 
-                    auto time_since_last = std::chrono::duration_cast<std::chrono::milliseconds>(
+                    auto const time_since_last = std::chrono::duration_cast<std::chrono::milliseconds>(
                         now - last_publish_times_[config.event_id]);
 
                     if (time_since_last >= config.cycle_time) {
@@ -303,7 +303,7 @@ class EventPublisherImpl : public transport::ITransportListener {
                                MessageType::NOTIFICATION, ReturnCode::E_OK);
         someip_message.set_payload(notification.event_data);
 
-        Result result = transport_->send_message(someip_message, client_endpoint);
+        Result const result = transport_->send_message(someip_message, client_endpoint);
         if (result != Result::SUCCESS) {
             // Log error or handle failure
         }
diff --git a/src/platform/freertos/memory.cpp b/src/platform/freertos/memory.cpp
index 1dd56f44a..c69f5baa8 100644
--- a/src/platform/freertos/memory.cpp
+++ b/src/platform/freertos/memory.cpp
@@ -22,6 +22,7 @@
 #include <task.h>
 
 #include <atomic>
+#include <cstdint>
 #include <cstring>
 #include <new>
 
@@ -60,16 +61,16 @@ void ensure_pool_init() {
 }
 
 void release_message_impl(someip::Message* msg) {
-    if (!msg) {
+    if (msg == nullptr) {
         return;
     }
 
-    auto* raw = reinterpret_cast<char*>(msg);
-    auto* pool_start = static_cast<char*>(pool_buffer);
-    if (raw < pool_start || raw >= pool_start + POOL_SIZE * sizeof(someip::Message)) {
+    auto raw_addr = reinterpret_cast<std::uintptr_t>(msg);
+    auto pool_addr = reinterpret_cast<std::uintptr_t>(pool_buffer);
+    if (raw_addr < pool_addr || raw_addr >= pool_addr + POOL_SIZE * sizeof(someip::Message)) {
         return;
     }
-    size_t const byte_offset = static_cast<size_t>(raw - pool_start);
+    size_t const byte_offset = raw_addr - pool_addr;
     if (byte_offset % sizeof(someip::Message) != 0) {
         return;
     }
diff --git a/src/platform/threadx/memory.cpp b/src/platform/threadx/memory.cpp
index 5dd9eb5ce..4dc1f832d 100644
--- a/src/platform/threadx/memory.cpp
+++ b/src/platform/threadx/memory.cpp
@@ -71,7 +71,7 @@ void ensure_pool_init() {
 }
 
 void release_message_impl(someip::Message* msg) {
-    if (!msg) {
+    if (msg == nullptr) {
         return;
     }
 
diff --git a/src/someip/message.cpp b/src/someip/message.cpp
index 6a21a343a..a6e45e3c1 100644
--- a/src/someip/message.cpp
+++ b/src/someip/message.cpp
@@ -64,20 +64,7 @@ Message::Message(MessageId message_id, RequestId request_id,
     update_length();
 }
 
-// NOLINTNEXTLINE(modernize-use-equals-default) - explicit copy for clarity
-Message::Message(const Message& other)
-    : message_id_(other.message_id_),
-      length_(other.length_),
-      request_id_(other.request_id_),
-      protocol_version_(other.protocol_version_),
-      interface_version_(other.interface_version_),
-      message_type_(other.message_type_),
-      return_code_(other.return_code_),
-      payload_(other.payload_),
-      e2e_header_(other.e2e_header_),
-      timestamp_(other.timestamp_) {
-    // Length is copied as-is for copy constructor
-}
+Message::Message(const Message& other) = default;
 
 Message::Message(Message&& other) noexcept
     : message_id_(other.message_id_),
diff --git a/src/tp/tp_manager.cpp b/src/tp/tp_manager.cpp
index 0f038ad76..c5e00a51b 100644
--- a/src/tp/tp_manager.cpp
+++ b/src/tp/tp_manager.cpp
@@ -45,7 +45,7 @@ void TpManager::shutdown() {
 }
 
 bool TpManager::needs_segmentation(const Message& message) const {
-    std::vector<uint8_t> data = message.serialize();
+    std::vector<uint8_t> const data = message.serialize();
     return data.size() > config_.max_segment_size;
 }
 
@@ -71,7 +71,7 @@ TpResult TpManager::segment_message(const Message& message, uint32_t& transfer_i
 
     // Segment the message
     std::vector<TpSegment> segments;
-    TpResult result = segmenter_->segment_message(message, segments);
+    TpResult const result = segmenter_->segment_message(message, segments);
 
     if (result != TpResult::SUCCESS) {
         return result;
@@ -198,11 +198,11 @@ void TpManager::process_timeouts() {
 
         cb = completion_callback_;
 
-        auto now = std::chrono::steady_clock::now();
+        auto const now = std::chrono::steady_clock::now();
 
         for (auto it = active_transfers_.begin(); it != active_transfers_.end(); ) {
             TpTransfer& transfer = it->second;
-            auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+            auto const elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
                 now - transfer.last_activity);
 
             if (elapsed > config_.reassembly_timeout) {
diff --git a/src/tp/tp_reassembler.cpp b/src/tp/tp_reassembler.cpp
index c4662ae14..5558bf4bd 100644
--- a/src/tp/tp_reassembler.cpp
+++ b/src/tp/tp_reassembler.cpp
@@ -49,8 +49,11 @@ bool TpReassembler::parse_tp_header(const std::vector<uint8_t>& payload,
     }
 
     // TP header starts at offset 16 (after SOME/IP header)
-    uint32_t tp_header = (payload[16] << 24) | (payload[17] << 16) |
-                        (payload[18] << 8) | payload[19];
+    uint32_t const tp_header =
+        (static_cast<uint32_t>(payload[16]) << 24) |
+        (static_cast<uint32_t>(payload[17]) << 16) |
+        (static_cast<uint32_t>(payload[18]) << 8) |
+        static_cast<uint32_t>(payload[19]);
 
     // Extract offset (28 bits, divided by 4 to get byte offset)
     uint32_t const offset_units = tp_header >> 4;
@@ -84,7 +87,7 @@ bool TpReassembler::process_segment(const TpSegment& segment, std::vector<uint8_
     platform::ScopedLock const lock(buffers_mutex_);
 
     TpReassemblyBuffer* buffer = find_or_create_buffer(segment);
-    if (!buffer) {
+    if (buffer == nullptr) {
         return false;
     }
 
@@ -176,7 +179,7 @@ bool TpReassembler::add_segment_to_buffer(TpReassemblyBuffer& buffer, const TpSe
         header_overhead = 4;  // TP header only for consecutive/last segments
     }
 
-    size_t actual_payload_bytes = segment.payload.size() > header_overhead
+    size_t const actual_payload_bytes = segment.payload.size() > header_overhead
                                   ? segment.payload.size() - header_overhead
                                   : 0;
 
@@ -252,8 +255,8 @@ bool TpReassembler::get_reassembly_progress(uint32_t message_id, uint32_t& recei
 
     // Count received bytes
     received_bytes = 0;
-    for (size_t i = 0; i < buffer.received_segments.size(); ++i) {
-        if (buffer.received_segments[i]) {
+    for (bool received : buffer.received_segments) {
+        if (received) {
             received_bytes += config.max_segment_size;  // Approximate
         }
     }
@@ -302,10 +305,10 @@ void TpReassembler::cleanup_completed_buffers() {
 }
 
 void TpReassembler::cleanup_timed_out_buffers(const TpConfig& config) {
-    auto now = std::chrono::steady_clock::now();
+    auto const now = std::chrono::steady_clock::now();
 
     for (auto it = reassembly_buffers_.begin(); it != reassembly_buffers_.end(); ) {
-        auto elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
+        auto const elapsed = std::chrono::duration_cast<std::chrono::milliseconds>(
             now - it->second->start_time);
 
         if (elapsed > config.reassembly_timeout) {
diff --git a/src/tp/tp_segmenter.cpp b/src/tp/tp_segmenter.cpp
index c86901988..8e83afa72 100644
--- a/src/tp/tp_segmenter.cpp
+++ b/src/tp/tp_segmenter.cpp
@@ -82,9 +82,9 @@ TpResult TpSegmenter::create_multi_segments(const Message& message,
                                           const std::vector<uint8_t>& payload,
                                           std::vector<TpSegment>& segments) {
 
-    uint32_t total_length = static_cast<uint32_t>(payload.size());
+    uint32_t const total_length = static_cast<uint32_t>(payload.size());
     uint16_t payload_offset = 0;  // Offset into the payload data
-    uint8_t const sequence_number = next_sequence_number_++;
+    uint8_t const sequence_number = next_sequence_number_;
 
     // Create a copy of the message with TP flag added to message type
     Message tp_message = message;
@@ -101,8 +101,10 @@ TpResult TpSegmenter::create_multi_segments(const Message& message,
         std::vector<uint8_t> header = tp_message.serialize();
         header.resize(16);  // Keep only header (16 bytes)
 
-        // Add first part of payload (accounting for TP header)
-        size_t first_payload_size = std::min(static_cast<size_t>(config_.max_segment_size - 16 - 4),
+        size_t const first_overhead = 16 + 4;
+        size_t const first_capacity = config_.max_segment_size > first_overhead
+            ? config_.max_segment_size - first_overhead : 0;
+        size_t const first_payload_size = std::min(first_capacity,
                                            static_cast<size_t>(total_length));
         header.insert(header.end(), payload.begin(),
                       payload.begin() + static_cast<std::ptrdiff_t>(first_payload_size));
@@ -141,9 +143,10 @@ TpResult TpSegmenter::create_multi_segments(const Message& message,
         segment.header.segment_offset = payload_offset;
         segment.header.sequence_number = sequence_number;
 
-        // Calculate payload size for this segment (accounting for TP header)
-        uint16_t payload_size = static_cast<uint16_t>(
-            std::min(static_cast<uint32_t>(config_.max_segment_size - 4), remaining_bytes));
+        uint32_t const segment_capacity = config_.max_segment_size > 4
+            ? config_.max_segment_size - 4 : 0;
+        uint16_t const payload_size = static_cast<uint16_t>(
+            std::min(segment_capacity, remaining_bytes));
 
         // Create segment with TP header
         std::vector<uint8_t> segment_data;
diff --git a/src/transport/endpoint.cpp b/src/transport/endpoint.cpp
index ec864912e..9d106817b 100644
--- a/src/transport/endpoint.cpp
+++ b/src/transport/endpoint.cpp
@@ -38,10 +38,7 @@ Endpoint::Endpoint(const std::string& address, uint16_t port, TransportProtocol
     : address_(address), port_(port), protocol_(protocol) {
 }
 
-// NOLINTNEXTLINE(modernize-use-equals-default) - explicit copy for clarity
-Endpoint::Endpoint(const Endpoint& other)
-    : address_(other.address_), port_(other.port_), protocol_(other.protocol_) {
-}
+Endpoint::Endpoint(const Endpoint& other) = default;
 
 Endpoint::Endpoint(Endpoint&& other) noexcept
     : address_(std::move(other.address_)), port_(other.port_), protocol_(other.protocol_) {
@@ -138,21 +135,21 @@ bool Endpoint::is_valid_ipv4(const std::string& address) const {
     size_t pos = 0;
 
     while (pos < address.size() && octets < 4) {
-        if (!std::isdigit(static_cast<unsigned char>(address[pos]))) {
+        if (std::isdigit(static_cast<unsigned char>(address[pos])) == 0) {
             return false;
         }
 
-        size_t start = pos;
-        while (pos < address.size() && std::isdigit(static_cast<unsigned char>(address[pos]))) {
+        size_t const start = pos;
+        while (pos < address.size() && std::isdigit(static_cast<unsigned char>(address[pos])) != 0) {
             ++pos;
         }
 
-        size_t digit_len = pos - start;
+        size_t const digit_len = pos - start;
         if (digit_len == 0 || digit_len > 3) {
             return false;
         }
 
-        int val = std::atoi(address.substr(start, digit_len).c_str());
+        int const val = std::atoi(address.substr(start, digit_len).c_str());
         if (val < 0 || val > 255) {
             return false;
         }
@@ -180,14 +177,14 @@ bool Endpoint::is_valid_ipv6(const std::string& address) const {
         return false;
     }
 
-    for (char c : address) {
-        if (!std::isxdigit(static_cast<unsigned char>(c)) && c != ':') {
+    for (char const c : address) {
+        if (std::isxdigit(static_cast<unsigned char>(c)) == 0 && c != ':') {
             return false;
         }
     }
 
-    size_t double_colon = address.find("::");
-    bool has_double_colon = (double_colon != std::string::npos);
+    size_t const double_colon = address.find("::");
+    bool const has_double_colon = (double_colon != std::string::npos);
     if (has_double_colon && address.find("::", double_colon + 2) != std::string::npos) {
         return false;
     }
@@ -262,12 +259,12 @@ bool Endpoint::is_multicast_ipv4(const std::string& address) const {
     }
 
     // Extract first octet
-    size_t first_dot = address.find('.');
+    size_t const first_dot = address.find('.');
     if (first_dot == std::string::npos) {
         return false;
     }
 
-    int first_octet = std::stoi(address.substr(0, first_dot));
+    int const first_octet = std::stoi(address.substr(0, first_dot));
 
     // IPv4 multicast range: 224.0.0.0 to 239.255.255.255
     return first_octet >= 224 && first_octet <= 239;