Systematic Debugging (Mitchell Hashimoto's pattern)

1. •Reproduce: Confirm the issue is reproducible
2. •Isolate: Find the minimal reproduction case
3. •Diagnose: Read relevant code, trace execution path
4. •Fix: Make the smallest possible change
5. •Verify: Confirm fix without regressions

Rules

• •Read error messages and stack traces before acting
• •Never guess at fixes -- understand root cause first
• •Launch parallel Explore agents for different hypotheses (run_in_background: true)
• •Check git log for recent changes that might have caused it
• •For complex fixes, write spec.md with diagnosis before implementing

Anti-patterns

• •Don't add try/catch to hide errors
• •Don't add defensive null checks without understanding why null occurs
• •Don't retry flaky operations without understanding the failure mode