Simon Willison Used Claude Fable to Review His Own Code Before Shipping sqlite-utils 4.0 — Found 5 Release-Blocking Bugs, for $149

Summary

Simon Willison documents using Claude Fable as a final pre-release code reviewer for sqlite-utils 4.0, running 37 prompts across 34 commits (1,300+ lines changed across 30 files) with a single instruction: "final review before shipping a stable 4.0 release." Fable caught five release-blocking issues Simon had missed himself, including a severe bug where `delete_where()` silently failed to commit its transaction — a real data-loss bug that would have shipped in a stable release. He upgraded his C