Postmortem (blameless)
A written review after an incident: what happened, why, how it was handled and what changes so it does not repeat.
Blameless means the question is which conditions let a reasonable person make that mistake, not who made it. People then report problems early instead of hiding them. A good postmortem has a timeline, the impact on users, contributing causes and a few concrete actions with owners and dates.
Related terms
- Runbook: A short document that tells someone else how to run a system: where it lives, how to deploy, how to recover.
- Observability (o11y): Being able to tell what a running system is doing, and why, from the data it emits: logs, metrics and traces.
- RPO and RTO: How much data you can afford to lose (RPO) and how long you can be down (RTO) after a disaster.
- MTTR (mean time to recovery): The average time from a production failure to the service working again for users; DORA now tracks a narrower version, failed deployment recovery time.
- Incident severity levels (SEV, P0–P3): Agreed levels, such as SEV1 to SEV4 or P0 to P3, that say how bad an incident is and what response it gets: who is paged, who leads, how often customers hear.
