Tools & Insights for Building
with AI

Practical guides, open-source utilities, and experiments in AI & software engineering - created and tested by me, Stephen Collins.

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thumbnail image for hotspots diff: Compare Complexity Between Any Two Branches, Tags, or Commits

hotspots diff: Compare Complexity Between Any Two Branches, Tags, or Commits

Stephen Collins • Mar 26, 2026
8 mins
Delta mode compares a commit to its parent. That's fine for local development — but CI needs to compare a PR branch to main, ...
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What Happens When You Run Hotspots on 102,000 Functions

Stephen Collins • Mar 14, 2026
3 mins
I stress-tested Hotspots against VS Code (102k functions) and found an O(N³) bug, a sampling tail exclusion bug, and a philos...
Read More thumbnail image for AI Made Code Cheap. The Bottleneck Is Now Understanding Systems.

AI Made Code Cheap. The Bottleneck Is Now Understanding Systems.

Stephen Collins • Mar 8, 2026
6 mins
AI removed code production as the engineering bottleneck. The new constraint is comprehension — and most developer tooling wa...
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