diff --git a/src/utils/svgRenderer.massive-scaling.test.ts b/src/utils/svgRenderer.massive-scaling.test.ts
new file mode 100644
index 000000000..2ee555d60
--- /dev/null
+++ b/src/utils/svgRenderer.massive-scaling.test.ts
@@ -0,0 +1,82 @@
+import { describe, it, expect } from 'vitest';
+import { generateOptimizedSvg, ContributionNode } from './svgRenderer';
+
+function generateContributionData(weeks: number): ContributionNode[] {
+  const data: ContributionNode[] = [];
+  for (let x = 0; x < 7; x++) {
+    for (let y = 0; y < weeks; y++) {
+      data.push({
+        date: `2024-${String((y % 12) + 1).padStart(2, '0')}-${String((x % 28) + 1).padStart(2, '0')}`,
+        count: Math.floor(Math.random() * 50),
+        x,
+        y,
+      });
+    }
+  }
+  return data;
+}
+
+describe('generateOptimizedSvg massive-scaling: Massive Data Sets and Extreme High Bounds Scaling', () => {
+  it('renders without crashing for a massive dataset of 5000+ contribution nodes', () => {
+    const data = generateContributionData(800);
+
+    expect(data.length).toBeGreaterThan(5000);
+
+    const svg = generateOptimizedSvg(data);
+
+    expect(svg).toContain('<svg');
+    expect(svg).toContain('</svg>');
+  });
+
+  it('completes rendering within acceptable time limits under extreme load of 10000 nodes', () => {
+    const data = generateContributionData(1429);
+
+    const start = performance.now();
+    const svg = generateOptimizedSvg(data);
+    const duration = performance.now() - start;
+
+    expect(svg.length).toBeGreaterThan(0);
+    expect(duration).toBeLessThan(5000);
+  });
+
+  it('produces valid SVG coordinates that scale cleanly with extremely high contribution counts', () => {
+    const data: ContributionNode[] = [];
+    for (let x = 0; x < 7; x++) {
+      data.push({
+        date: `2024-01-${String(x + 1).padStart(2, '0')}`,
+        count: 999999,
+        x,
+        y: 0,
+      });
+    }
+
+    const svg = generateOptimizedSvg(data);
+
+    expect(svg).toContain('viewBox');
+    expect(svg).toContain('<svg');
+    expect(svg).toContain('</svg>');
+    expect(svg).not.toContain('NaN');
+    expect(svg).not.toContain('Infinity');
+  });
+
+  it('handles a fully populated 53-week grid without overlapping or missing elements', () => {
+    const data = generateContributionData(53);
+
+    const svg = generateOptimizedSvg(data);
+
+    const groupCount = svg.match(/<g transform="translate/g)?.length ?? 0;
+    const flatTileCount = svg.match(/<use href="#iso-top"/g)?.length ?? 0;
+
+    expect(groupCount + flatTileCount).toBeGreaterThan(0);
+    expect(svg).toContain('id="monolith-grid"');
+  });
+
+  it('returns an empty grid container without breaking the layout tree when given an empty dataset', () => {
+    const svg = generateOptimizedSvg([]);
+
+    expect(svg).toContain('<svg');
+    expect(svg).toContain('</svg>');
+    expect(svg).toContain('id="monolith-grid"');
+    expect(svg).not.toContain('NaN');
+  });
+});