Two AI reviews passed my change. The correct architecture was documented one file away.

Short summary

Two AI code reviewers both missed a subtle .mjs module resolution bug because they evaluated code in a local ESM environment while the deployed runtime used CommonJS. The deeper lesson: stacking reviewers with overlapping scopes multiplies confidence without expanding coverage; true defense in depth requires uncorrelated checks evaluating different signals.

• •AI code review missed a module packaging error (.mjs imported via require()) that only surfaced at runtime in deployed environment
• •Both models shared the same scope (local logic correctness); overlapping scopes create false confidence, not redundancy
• •Real verification requires uncorrelated checks with different scopes: semantic analysis, environment awareness, documentation review

Generated with AI, which can make mistakes.