nickcrew Incident Response
Structured incident management from detection through postmortem, with resilience patterns for preventing and containing cascading failures.
When to Use
- Production incident in progress (outage, degradation, data loss)
- Designing circuit breakers, bulkheads, or fallback strategies
- Conducting or planning chaos engineering exercises
- Writing or reviewing postmortem documents
- Establishing on-call procedures and escalation paths
Avoid when:
- The issue is a development-time bug with no production impact
- Designing general system architecture (use system-design instead)
Quick Reference
| Topic | Load reference |
|---|---|
| Triage Framework | skills/incident-response/references/triage-framework.md |
| Postmortem Patterns | skills/incident-response/references/postmortem-patterns.md |
Incident Response Workflow
Phase 1: Detect
- Alert fires or user report received
- Confirm the issue is real (not a false positive)
- Identify affected services and user impact scope
Phase 2: Triage
- Classify severity (P0-P3)
- Assign incident commander
- Open communication channel (war room, Slack channel)
- Begin status page updates
Phase 3: Contain
- Stop the bleeding: rollback, feature flag, traffic shift
- Prevent cascade: circuit breakers, load shedding, bulkhead isolation
- Communicate: stakeholder updates every 15 minutes for P0/P1
Phase 4: Resolve
- Implement fix (minimal viable fix first)
- Validate in staging if time permits
- Deploy with monitoring and rollback plan ready
- Confirm recovery with metrics returning to baseline
Phase 5: Postmortem
- Document timeline within 48 hours
- Conduct blameless review with all participants
- Identify root cause and contributing factors
- Assign action items with owners and deadlines
- Update runbooks and alerting based on lessons learned
Severity Framework
| Level | Impact | Response Time | Examples |
|---|---|---|---|
| P0 | Complete outage, data loss, security breach | Immediate (< 5 min) | Service down, data corruption, credential leak |
| P1 | Major feature broken, significant user impact | < 30 min | Payment processing failed, auth broken for region |
| P2 | Degraded performance, partial feature loss | < 4 hours | Elevated latency, non-critical feature unavailable |
| P3 | Minor issue, workaround available | Next business day | UI glitch, slow report generation, cosmetic error |
Output
- Incident timeline and severity classification
- Containment actions taken
- Postmortem document with action items
- Updated runbooks and alerting rules
Common Mistakes
- Skipping severity classification and treating everything as P0
- Making changes without a rollback plan
- Forgetting to communicate status to stakeholders
- Writing postmortems that assign blame instead of identifying systemic issues
- Not following up on postmortem action items