Interview Question
A production API is intermittently timing out. Explain how you would isolate the failure and prevent recurrence.
What a Strong Answer Should Cover
- Define the symptom and blast radius
- Trace the request path
- Use metrics and logs to narrow the bottleneck
- Apply the smallest safe fix
- Add prevention and verification steps
Common Mistakes
- Jumping to a technology before clarifying the problem
- Explaining the solution without the reasoning or trade-offs
- Omitting verification, failure handling, or prevention
Interviewer Follow-ups
- What signal would you trust first and why?
- What is the smallest safe mitigation?
- What prevention work should follow the incident?
What the interviewer is testing
- Problem isolation and evidence-based reasoning
- Safe mitigation and verification
- Prevention and operational learning
Real-World Sample Answer
A strong real-world response should connect requirements to engineering decisions, explain why the chosen approach fits the constraints, and make failure, security, cost, observability, and verification explicit.