Code Room
On-callMediumoc-p032
Subject Incident responseLevel Mid–Senior~20 minCommon in Reliability & on-call interviewsIndustries Technology

Question

A deploy is half rolled out — some servers run the new version, some the old — and users get inconsistent behavior or errors depending on which they hit. What do you do?

What a strong answer looks like

Stop the bleeding first (mitigate), then form hypotheses from real signals. Separate root cause from symptom, communicate status as you go, and close with what prevents a repeat.

Diagram & narrate the incident
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Run or narrate your approach, then ask the coach.