diff --git a/components/dashboard/PRInsights/Highlights.massive-scaling.test.tsx b/components/dashboard/PRInsights/Highlights.massive-scaling.test.tsx
new file mode 100644
index 000000000..daeba1dc8
--- /dev/null
+++ b/components/dashboard/PRInsights/Highlights.massive-scaling.test.tsx
@@ -0,0 +1,124 @@
+import React from 'react';
+import { describe, expect, it, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import Highlights from './Highlights';
+import type { PRInsightData } from '@/services/github/pr-insights';
+
+vi.mock('framer-motion', () => ({
+  motion: {
+    a: ({
+      children,
+      className,
+      href,
+      target,
+      rel,
+      ...props
+    }: React.AnchorHTMLAttributes<HTMLAnchorElement> & { children?: React.ReactNode }) => {
+      const validProps = Object.keys(props).reduce(
+        (acc, key) => {
+          if (!['initial', 'animate', 'transition', 'whileInView', 'viewport'].includes(key)) {
+            acc[key] = (props as Record<string, unknown>)[key];
+          }
+          return acc;
+        },
+        {} as Record<string, unknown>
+      );
+      return (
+        <a className={className} href={href} target={target} rel={rel} {...validProps}>
+          {children}
+        </a>
+      );
+    },
+  },
+}));
+
+vi.mock('lucide-react', () => ({
+  MessageSquare: () => <svg data-testid="icon-message-square" />,
+  Zap: () => <svg data-testid="icon-zap" />,
+  HardDrive: () => <svg data-testid="icon-hard-drive" />,
+  ArrowRight: () => <svg data-testid="icon-arrow-right" />,
+}));
+
+function buildMassiveHighlights(
+  overrides: Partial<PRInsightData['highlights']> = {}
+): PRInsightData['highlights'] {
+  return {
+    fastestMerged: {
+      title: 'A'.repeat(10000),
+      url: 'https://github.com/org/repo/pull/1',
+      time: 0.001,
+    },
+    mostDiscussed: {
+      title: 'B'.repeat(10000),
+      url: 'https://github.com/org/repo/pull/2',
+      comments: 999999,
+    },
+    largest: {
+      title: 'C'.repeat(10000),
+      url: 'https://github.com/org/repo/pull/3',
+      additions: 999999,
+      deletions: 888888,
+    },
+    ...overrides,
+  };
+}
+
+describe('Highlights Massive Data Sets and Extreme High Bounds Scaling', () => {
+  it('renders all three cards with extreme high bounds values without layout breakage', () => {
+    render(<Highlights highlights={buildMassiveHighlights()} />);
+
+    expect(screen.getByText('Fastest Merged PR')).toBeInTheDocument();
+    expect(screen.getByText('Most Discussed')).toBeInTheDocument();
+    expect(screen.getByText('Largest Impact')).toBeInTheDocument();
+
+    expect(screen.getByText('0.0 hrs')).toBeInTheDocument();
+    expect(screen.getByText(/999999.*comments/)).toBeInTheDocument();
+    expect(screen.getByText('+999999 -888888')).toBeInTheDocument();
+  });
+
+  it('renders extremely long PR titles without crashing using line-clamp', () => {
+    const { container } = render(<Highlights highlights={buildMassiveHighlights()} />);
+
+    const clampedElements = container.querySelectorAll('.line-clamp-2');
+    expect(clampedElements.length).toBeGreaterThan(0);
+
+    clampedElements.forEach((el) => {
+      expect(el.textContent?.length).toBeGreaterThan(0);
+    });
+  });
+
+  it('renders gracefully when all highlight fields are undefined', () => {
+    render(
+      <Highlights
+        highlights={{ fastestMerged: undefined, mostDiscussed: undefined, largest: undefined }}
+      />
+    );
+
+    expect(screen.getAllByText('N/A')).toHaveLength(3);
+    expect(screen.getAllByText('No data available')).toHaveLength(3);
+  });
+
+  it('all card links point to correct URLs under massive data', () => {
+    render(<Highlights highlights={buildMassiveHighlights()} />);
+
+    const links = screen.getAllByRole('link');
+    expect(links).toHaveLength(3);
+
+    expect(links[0]).toHaveAttribute('href', 'https://github.com/org/repo/pull/1');
+    expect(links[1]).toHaveAttribute('href', 'https://github.com/org/repo/pull/2');
+    expect(links[2]).toHaveAttribute('href', 'https://github.com/org/repo/pull/3');
+  });
+
+  it('falls back to # href when highlight data is undefined', () => {
+    render(
+      <Highlights
+        highlights={{ fastestMerged: undefined, mostDiscussed: undefined, largest: undefined }}
+      />
+    );
+
+    const links = screen.getAllByRole('link');
+    links.forEach((link) => {
+      expect(link).toHaveAttribute('href', '#');
+    });
+  });
+});