postmortem-analysis

# Skill: Postmortem Analysis > **Expertise:** Blameless culture, 5-whys root cause analysis, contributing factors, actionable items with owners and due dates. ## When to load When writing a postmortem after a P0/P1 incident, reviewing a draft postmortem, or designing action items. ## Postmortem Template ```markdown # Postmortem: [Service] — [Date] — [Severity] **Status:** Draft / In Review / Complete **Severity:** P0 / P1 **Duration:** [start] → [end] ([total duration]) **Impact:** [N users affected, revenue impact if known, SLO budget consumed: X minutes] **Incident Commander:** [name] **Authors:** [name(s)] --- ## Summary [2–3 sentences: what broke, what caused it, what fixed it] ## Timeline (UTC) | Time | Event | |:---|:---| | 14:22 | Alert fired: HighErrorRate on payment-service | | 14:24 | On-call acknowledged; war room opened | | 14:28 | Identified: error correlated with v2.4.1 deploy at 14:05 | | 14:31 | Mitigation: helm rollback payment-service to revision 3 | | 14:33 | Error rate returning to baseline | | 14:40 | Resolved; monitoring | ## Root Cause Analysis (5-Whys) **Symptom:** Payment service returning 502s at 4.2% rate 1. **Why?** → Upstream credit-card-service returning 503s 2. **Why?** → credit-card-service pods OOMKilled 3. **Why?** → Memory limit was 256Mi; new code path loaded full transaction history into memory 4. **Why?** → Code review missed memory complexity of the new query (no performance test) 5. **Why?** → No memory profiling step in CI...