Walk me through how you would run and write a postmortem after a major outage.
What the interviewer wants to hear
- Blameless culture and clear trigger criteria
- Detailed timeline with detection, mitigation and resolution times
- Impact on users and error budget
- Contributing factors rather than a single root cause
- Action items with owners, priorities and due dates, tracked to completion
- Share widely and review
Model answer
I start soon after the incident while memories are fresh, and I keep it blameless: we ask how the system let a reasonable person make that choice, not who made a mistake. The document includes a summary, user impact and error budget used, and a detailed timeline from the first trigger through detection, mitigation and full recovery. Then we analyse contributing factors, since outages usually have several, such as a risky change, a missing alert and a slow rollback process. We list what went well and where we got lucky. Each action item has an owner, priority and due date and is tracked in our ticket system. Finally, we review it in a meeting and share it widely so other teams learn too.
Can you answer it under time pressure?
Take a timed medium round and get scored on every answer.
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