Debugging Checklist
Overview
Use this checklist to stay disciplined during debugging and avoid random changes.
Why It Matters
A repeatable debugging checklist reduces thrash and helps you reach the root cause faster.
Core Concepts
- Reproduce the issue.
- Identify the failing layer.
- Verify the fix in the real flow.
Mental Models
If you cannot explain where the failure occurs, you do not yet know enough to patch it safely.
Best Practices
- Capture the exact error, request, and state.
- Change one thing at a time.
- Test the smallest plausible fix first.
Common Mistakes
- Guessing before reproducing.
- Fixing only the visible screen.
- Forgetting to re-check the full user path.
Trade-offs
Deep debugging takes longer than guesswork, but it usually prevents repeated incidents and broken patches.
Decision Framework
| Step | Done? |
|---|---|
| Reproduce | Yes / no |
| Locate layer | Yes / no |
| Validate fix | Yes / no |
Examples
- Check the browser console, network tab, and backend logs in that order.
Checklists
- Can I reproduce it?
- Do I know the failing boundary?
- Did I verify the fix end to end?
Senior Engineer Notes
Senior engineers debug methodically so the same bug does not return in a different costume.