Debug

Phase 3: Hypothesis and Testing

1. State your hypothesis: "The bug is caused by [specific thing] because [evidence]."
2. Design a minimal test: one change, one verification.
3. Do NOT make multiple simultaneous changes. One at a time.

Phase 4: Fix and Verify

1. Write a failing test first (if the bug is testable).
2. Apply the single targeted fix.
3. Verify: run the relevant test or Playwright flow. Read full output.
4. Confirm no regressions in adjacent code.

Red Flags - Stop if You're Doing These

• Trying a fix before completing Phase 1
• Making multiple changes at once
• "Just trying" something without evidence
• Reverting and retrying the same approach (3-strike rule applies)

Escalation

After 3 failed fix attempts: stop, commit partial progress, report to user. Do not continue thrashing. The architecture itself may be flawed - that requires a different kind of decision, not more debugging.

For hard architectural bugs: call opus-advisor with "Think deeply and use extended thinking."