If the current repo has its own rules/skills covering this topic (check .claude/rules/ and repo CLAUDE.md), those take precedence — apply this skill only where they're silent.

Systematic Debugging

If 3+ fixes have failed: Stop fixing symptoms. Question the architecture. The bug may be a design problem, not a code problem.

For multi-component systems: Add diagnostic logging at each component boundary before proposing fixes. See references/debugging-techniques.md for instrumentation patterns (binary search, git bisect, minimal reproduction, strategic logging, differential analysis).

For large or multi-file log investigations: Delegate to the @ce:log-reader agent for efficient analysis. Not needed for a single short stack trace.

Reporting Format

## Root Cause
[1-3 sentences explaining underlying issue]
Located in: `file.ts:123`

## What Was Wrong
[Specific problem - mutation, race condition, missing validation, etc. 1-3 sentences]