What is a Postmortem?

A postmortem is a retrospective analysis conducted after an incident, outage, or project completion to understand what happened, what went well, what went wrong, and how to prevent similar issues in the future.

Postmortems aim to identify root causes, learn from failures, and implement changes to enhance team performance and system reliability -- all in a blameless environment.

• Timeline -- What happened and when
• Impact -- Who was affected and how severely
• Root Cause -- The underlying reason for the failure
• Contributing Factors -- What made things worse
• Action Items -- Specific steps to prevent recurrence
• Lessons Learned -- Key takeaways for the team

After a 2-hour production outage caused by a database migration, the team conducts a blameless postmortem. They discover the migration was not tested against production-scale data. Action items include adding migration dry-runs in staging and implementing automated rollback procedures.

Organizations that consistently conduct blameless postmortems build a culture of learning and psychological safety, leading to more resilient systems and teams that are unafraid to innovate.