Debug Strategy

• Create minimal reproduction case
• Isolate variables (data, environment, timing)
• Add logging at key points

3. Binary Search the Problem

• Comment out half the code
• Does it still fail? Problem is in remaining half
• Repeat until isolated

4. Check the Obvious

• Is it saved? Is it deployed?
• Correct environment variables?
• Dependencies installed/updated?
• Cache cleared?
• Correct branch?

5. Trace Data Flow

• Log inputs at entry point
• Log outputs at each transformation
• Find where actual diverges from expected

Common Bug Patterns

Debug Tools by Domain

JavaScript/React:

• Browser DevTools (Console, Network, React DevTools)
• console.log, console.table, debugger
• React Query DevTools, Redux DevTools

React Native:

• Flipper, React Native Debugger
• adb logcat (Android), Console.app (iOS)
• Remote JS debugging

Node.js:

• --inspect flag + Chrome DevTools
• DEBUG=* environment variable
• node --trace-warnings

Database:

• Query explain plans
• Slow query logs
• Connection pool monitoring

Output Format

When reporting findings:

1. Root Cause - What actually caused the bug
2. Fix - Code change required
3. Prevention - How to avoid similar bugs
4. Testing - How to verify the fix