5.4QA's Unique Contribution

The QA engineer's primary contribution is asking questions nobody else asks. Developers think about how to build it. POs think about what to build. QA thinks about how it could break.

Question Categories for QA

Category	Example Questions
Boundary values	What happens at 0, 1, max, max+1?
Error handling	What happens when the API returns 500? When the network is down?
State transitions	What happens if the user navigates away mid-action?
Concurrency	What if two users modify the same record simultaneously?
Security	What if someone tries to access another user's data?
Performance	What happens with 10,000 items? With 100 concurrent users?
Accessibility	Can this be used with keyboard only? With a screen reader?
Backward compatibility	Does this break existing API consumers?
Data integrity	What happens to existing data during migration?
User context	What about mobile? Slow network? Offline?

Building a Question Checklist

Over time, build a personal checklist of "what if" questions. After each three amigos session, add any questions that revealed missing requirements. This checklist becomes your most valuable QA tool.