Question
Describe a time you debugged a complex production incident in a distributed system — ideally involving data inconsistency, intermittent failures, or race conditions.
What this round evaluates
- Your mental model of distributed failure modes (network partition, partial failure, out-of-order events)
- Debugging tools and methodology (logs, traces, metrics — not guesswork)
- Speed of diagnosis vs correctness of fix
- Post-incident improvement (what monitoring would have caught this earlier?)
Strong answer structure
- Incident description and blast radius
- First signal and your initial hypothesis
- Tools and steps used to isolate root cause
- The fix applied under pressure
- Permanent remediation and added observability