On-callHardoc-p050

Subject ObservabilityLevel Senior–Staff~20 minCommon in Reliability & on-call interviewsIndustries Technology

Question

Health checks are green and the service looks 'up' on every dashboard, but users report they can't complete a key action like checkout. What's going on and how do you investigate?

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.

Learn the concepts

Diagram & narrate the incident

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Run or narrate your approach, then ask the coach.