Respond to a Reliability Regression Shortly After Deployment
MicrosoftSoftware Engineer · Onsite
Last updated
Respond to a post-deployment latency or reliability regression with scoped diagnosis, safe rollback decisions, customer-impact measurement, and prevention.
A new version has been deployed, and 10–15 minutes later latency or reliability worsens. Explain how you would detect the problem, decide whether to roll back, measure customer impact, and prevent recurrence.
Constraints & Assumptions
- Treat the temporal link to deployment as evidence to investigate, not proof of the root cause.
- Prioritize restoring service while retaining enough evidence to diagnose the failure.
- State what signals and rollback prerequisites you need; no specific service architecture or error budget is supplied.
Clarifying Questions to Ask
- Which endpoint, region, user cohort, or dependency is affected?
- Did the release include schema, data, configuration, or compatibility changes that complicate rollback?
- Is the previous version known healthy, and can traffic be shifted safely?
Hints
Hint 1
Separate mitigation from explanation: The evidence required to safely restore service can be narrower than the evidence required to prove the final root cause.
Follow-up questions
- When would you avoid an immediate binary rollback?
- How would you distinguish a release regression from a coincident dependency incident?
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