diff --git a/components/dashboard/PRInsights/PRStatusDistribution.massive-scaling.test.tsx b/components/dashboard/PRInsights/PRStatusDistribution.massive-scaling.test.tsx
new file mode 100644
index 000000000..e239a935f
--- /dev/null
+++ b/components/dashboard/PRInsights/PRStatusDistribution.massive-scaling.test.tsx
@@ -0,0 +1,150 @@
+import { describe, expect, it, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import type { ReactNode } from 'react';
+import PRStatusDistribution from './PRStatusDistribution';
+import type { PRInsightData } from '@/services/github/pr-insights';
+
+vi.mock('framer-motion', () => ({
+  motion: {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    div: ({ children, className, ...props }: any) => {
+      const validProps = Object.keys(props).reduce(
+        (acc, key) => {
+          if (!['initial', 'animate', 'transition', 'whileInView', 'viewport'].includes(key)) {
+            acc[key] = props[key as keyof typeof props];
+          }
+          return acc;
+        },
+        {} as Record<string, unknown>
+      );
+      return (
+        <div className={className} {...validProps}>
+          {children}
+        </div>
+      );
+    },
+  },
+}));
+
+vi.mock('recharts', () => ({
+  ResponsiveContainer: ({ children }: { children: ReactNode }) => (
+    <div data-testid="responsive-container">{children}</div>
+  ),
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  PieChart: ({ children, ...props }: any) => (
+    <div data-testid="pie-chart" {...props}>
+      {children}
+    </div>
+  ),
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  Pie: ({ ...props }: any) => <div data-testid="pie" {...props} />,
+  Cell: () => null,
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  Tooltip: ({ ...props }: any) => <div data-testid="recharts-tooltip" {...props} />,
+}));
+
+function buildMassiveData(overrides: Partial<PRInsightData> = {}): PRInsightData {
+  return {
+    totalPRs: 999999,
+    openPRs: 333333,
+    mergedPRs: 499999,
+    closedPRs: 166667,
+    mergeRate: 49.9999,
+    avgReviewTime: 9999.99,
+    avgTimeToFirstReview: 8888.88,
+    avgCycleTime: 7777.77,
+    weeklyActivity: Array.from({ length: 1000 }, (_, i) => ({
+      name: `Day-${i}`,
+      prs: i * 100,
+    })),
+    monthlyActivity: Array.from({ length: 500 }, (_, i) => ({
+      name: `Month-${i}`,
+      prs: i * 1000,
+    })),
+    reviewsGiven: 999999,
+    reviewsReceived: 888888,
+    avgReviewResponseTime: 9999.0,
+    fastestReview: 0.001,
+    slowestReview: 99999.99,
+    repoPerformance: Array.from({ length: 500 }, (_, i) => ({
+      name: `repo-${i}`,
+      totalPRs: i * 1000,
+      mergeRate: (i % 100) + 0.5,
+      reviewCount: i * 500,
+      avgReviewTime: i * 2.5,
+    })),
+    highlights: {
+      mostDiscussed: {
+        title: 'A'.repeat(500),
+        url: 'https://github.com/org/repo/pull/99999',
+        comments: 999999,
+      },
+      fastestMerged: undefined,
+      largest: undefined,
+    },
+    ...overrides,
+  };
+}
+
+describe('PRStatusDistribution Massive Data Sets and Extreme High Bounds Scaling', () => {
+  it('renders correctly with extremely large PR counts without layout overflow', () => {
+    const data = buildMassiveData();
+    const { container } = render(<PRStatusDistribution data={data} />);
+
+    expect(screen.getByText('999999')).toBeInTheDocument();
+    expect(screen.getByText(/total/i)).toBeInTheDocument();
+
+    // No overflow or broken structure
+    const root = container.firstChild as HTMLElement;
+    expect(root).toBeInTheDocument();
+  });
+
+  it('displays all three legend labels when all values are at extreme high bounds', () => {
+    const data = buildMassiveData();
+    render(<PRStatusDistribution data={data} />);
+
+    expect(screen.getByText('Merged')).toBeInTheDocument();
+    expect(screen.getByText('Open')).toBeInTheDocument();
+    expect(screen.getByText('Closed')).toBeInTheDocument();
+
+    expect(screen.getByText('(499999)')).toBeInTheDocument();
+    expect(screen.getByText('(333333)')).toBeInTheDocument();
+    expect(screen.getByText('(166667)')).toBeInTheDocument();
+  });
+
+  it('filters out zero-value segments and renders only non-zero entries', () => {
+    const data = buildMassiveData({ openPRs: 0, closedPRs: 0, mergedPRs: 999999 });
+    render(<PRStatusDistribution data={data} />);
+
+    expect(screen.getByText('Merged')).toBeInTheDocument();
+    expect(screen.queryByText('Open')).not.toBeInTheDocument();
+    expect(screen.queryByText('Closed')).not.toBeInTheDocument();
+  });
+
+  it('renders correctly when totalPRs is zero and all segments are empty', () => {
+    const data = buildMassiveData({
+      totalPRs: 0,
+      openPRs: 0,
+      mergedPRs: 0,
+      closedPRs: 0,
+    });
+    render(<PRStatusDistribution data={data} />);
+
+    expect(screen.getByText('0')).toBeInTheDocument();
+    expect(screen.getByText(/total/i)).toBeInTheDocument();
+
+    // No legend items since all filtered out
+    expect(screen.queryByText('Merged')).not.toBeInTheDocument();
+    expect(screen.queryByText('Open')).not.toBeInTheDocument();
+    expect(screen.queryByText('Closed')).not.toBeInTheDocument();
+  });
+
+  it('SVG coordinates scale cleanly — pie chart and container are present', () => {
+    const data = buildMassiveData();
+    render(<PRStatusDistribution data={data} />);
+
+    expect(screen.getByTestId('responsive-container')).toBeInTheDocument();
+    expect(screen.getByTestId('pie-chart')).toBeInTheDocument();
+    expect(screen.getByTestId('pie')).toBeInTheDocument();
+  });
+});