❌ Blame Culture:
"Who broke production?"
→ People hide mistakes
→ Less learning
→ Slower improvement

✅ Blameless Culture:
"What systemic issues led to this?"
→ People share openly
→ More learning
→ Faster improvement

# Post-Mortem: [Incident Title]

**Date:** YYYY-MM-DD
**Duration:** X hours Y minutes
**Severity:** Critical | High | Medium | Low
**Status:** Draft | Under Review | Published
**Author:** [Name]
**Reviewers:** [Names]

## Executive Summary

One paragraph summary of the incident, impact, and resolution.

## Timeline

All times in UTC.

**2024-01-15**
- 14:23 - Alert fired: High error rate on API
- 14:25 - Engineer paged, incident channel created
- 14:30 - Investigation began
- 14:45 - Root cause identified: Database connection pool exhausted
- 15:00 - Fix deployed: Increased pool size
- 15:15 - Service recovered
- 15:30 - Monitoring confirmed stability

## Impact

### Users Affected
- 45,000 users (approximately 30% of active users)
- 500 enterprise customers

### Business Impact
- $50,000 in estimated lost revenue
- 2,500 support tickets
- Negative social media mentions

### Technical Impact
- API response time: 200ms → 30,000ms
- Error rate: 0.1% → 45%
- Database connections: 100 → 1,000 (max limit)

## Root Cause

### What Happened
A sudden spike in traffic (3x normal) caused the database connection pool to be exhausted. New requests couldn't acquire connections and timed out.

### Why It Happened
1. **Traffic spike**: Product launch drove unexpected traffic
2. **Insufficient capacity**: Connection pool sized for normal load
3. **No auto-scaling**: Pool size was hardcoded
4. **Monitoring gap**: No alert for connection pool saturation
5. **Load testing gap**: Launch traffic not load tested

### Contributing Factors
- Marketing campaign timing not communicated to engineering
- Previous capacity planning didn't account for product launches
- Lack of circuit breakers to fail gracefully

## Resolution

### Immediate Actions
1. Increased database connection pool: 100 → 500
2. Restarted application servers to clear stuck connections
3. Enabled connection pooling metrics

### Short-term Fixes (Within 1 week)
- [ ] Implement auto-scaling for connection pool
- [ ] Add alerts for connection pool utilization (>80%)
- [ ] Add circuit breakers to prevent cascading failures
- [ ] Create runbook for similar incidents

### Long-term Improvements (Within 1 month)
- [ ] Implement connection pooling best practices
- [ ] Set up load testing pipeline
- [ ] Establish launch checklist with capacity planning
- [ ] Improve communication between marketing and engineering

## What Went Well

- **Fast detection**: Alert fired within 2 minutes
- **Quick escalation**: Right people paged immediately
- **Clear communication**: Regular updates in incident channel
- **Good collaboration**: Multiple teams worked together
- **Fast recovery**: Service restored in under 1 hour

## What Could Be Better

- **Prevention**: Could have been prevented with load testing
- **Monitoring**: Connection pool metrics weren't monitored
- **Communication**: Marketing didn't inform engineering of launch
- **Documentation**: No runbook for connection pool issues
- **Capacity**: Pool size wasn't reviewed before launch

## Lessons Learned

1. **Load test launches**: Always load test before product launches
2. **Monitor resources**: Track all critical resource pools
3. **Cross-team communication**: Establish launch communication protocol
4. **Fail gracefully**: Implement circuit breakers and backpressure
5. **Capacity planning**: Review capacity before major events

## Action Items

| Action | Owner | Due Date | Status |
|--------|-------|----------|--------|
| Implement connection pool auto-scaling | @john | 2024-01-22 | ✅ Done |
| Add connection pool alerts | @jane | 2024-01-20 | ✅ Done |
| Create launch checklist | @mike | 2024-01-25 | 🚧 In Progress |
| Set up load testing pipeline | @sarah | 2024-02-01 | 📋 Todo |
| Document incident response runbook | @alex | 2024-01-30 | 📋 Todo |

## References

- [Incident #1234](https://incidents.example.com/1234)
- [Monitoring Dashboard](https://grafana.example.com/d/abc)
- [Architecture Diagram](https://drive.example.com/diagram)
- [Load Testing Results](https://load-test.example.com/results)

# Post-Mortem: Payment Processing Outage

**Date:** 2024-01-15
**Duration:** 2 hours 15 minutes
**Severity:** Critical
**Author:** Jane Smith

## Executive Summary

On January 15, 2024, our payment processing system experienced a complete outage lasting 2 hours and 15 minutes. The outage affected all payment methods and impacted approximately 10,000 transactions. The root cause was an expired SSL certificate on our payment gateway. Total estimated impact: $150,000 in lost revenue.

## Timeline (UTC)

- **10:00** - SSL certificate expires (unnoticed)
- **10:15** - First payment failure reported by customer
- **10:20** - Alert fires: 100% payment error rate
- **10:22** - On-call engineer paged
- **10:25** - Incident declared, war room created
- **10:30** - Investigation begins
- **10:45** - Checked payment gateway logs
- **11:00** - Discovered SSL certificate error
- **11:15** - New certificate purchased and generated
- **11:30** - Certificate deployed to production
- **11:45** - Payment processing restored
- **12:00** - Monitoring confirms stability
- **12:15** - Incident resolved

## Impact

### User Impact
- 10,000 failed transactions
- 2,000 abandoned carts
- 500 support tickets
- Negative reviews on social media

### Business Impact
- $150,000 estimated lost revenue
- Reputational damage
- Lost customer trust
- 15 enterprise customers complained

### Technical Metrics
- Payment success rate: 99.9% → 0%
- Error rate: 0.1% → 100%
- Support ticket volume: 50/hour → 500/hour

## Root Cause

### What Happened
The SSL certificate for our payment gateway expired at 10:00 UTC. All HTTPS connections to the payment processor failed with a certificate validation error, causing 100% of payments to fail.

### Why It Happened
1. **No renewal reminder**: Certificate expiry not tracked
2. **No monitoring**: No alert for certificate expiry
3. **Manual process**: Certificate renewal was manual
4. **Knowledge gap**: Only one person knew about renewal
5. **No automation**: No automated certificate rotation

### Why We Didn't Catch It
- Certificate expiry was not monitored
- No alerts configured for SSL issues
- Load testing used test environment (different cert)
- No pre-production validation of certificates

## Resolution

### Immediate Fix
1. Purchased new SSL certificate
2. Generated CSR and private key
3. Deployed certificate to production gateway
4. Validated HTTPS connections working
5. Monitored payment success rate recovery

### Preventing Recurrence

#### Short-term (This week)
- [x] Set up certificate expiry monitoring
- [x] Add alerts 30 days before expiry
- [x] Document certificate renewal process
- [x] Create runbook for certificate issues

#### Long-term (This month)
- [ ] Implement automated certificate renewal (Let's Encrypt)
- [ ] Set up certificate inventory system
- [ ] Add certificate validation to CI/CD
- [ ] Establish on-call playbook for SSL issues

## What Went Well

✅ **Fast response**: Engineer responded in 2 minutes
✅ **Clear communication**: Regular updates to stakeholders
✅ **Good documentation**: Detailed incident log maintained
✅ **Team collaboration**: Multiple teams worked together
✅ **Customer service**: Support team handled inquiries well

## What Could Be Better

❌ **Prevention**: Should have been caught beforehand
❌ **Monitoring**: No certificate expiry monitoring
❌ **Automation**: Manual certificate management
❌ **Knowledge**: Single point of failure (one person knew)
❌ **Testing**: Production-like SSL config not tested

## Lessons Learned

### 1. Monitor Everything Critical
If it can cause an outage, monitor it. SSL certificates are critical infrastructure.

### 2. Automate Manual Processes
Manual processes are error-prone. Automate certificate renewal.

### 3. Share Knowledge
Don't let critical knowledge live in one person's head.

### 4. Test Realistically
Test environment should match production, including certificates.

### 5. Have Runbooks
Document resolution steps for common failure scenarios.

## Action Items

| Action | Owner | Due | Status |
|--------|-------|-----|--------|
| Set up cert expiry monitoring | @jane | Jan 18 | ✅ Done |
| Implement Let's Encrypt | @john | Jan 25 | 🚧 In Progress |
| Create cert inventory | @mike | Jan 22 | ✅ Done |
| Document renewal process | @sarah | Jan 20 | ✅ Done |
| Add SSL tests to CI/CD | @alex | Jan 30 | 📋 Todo |
| Create SSL runbook | @jane | Jan 25 | 📋 Todo |

## Metrics

### Before Incident
- Payment success rate: 99.9%
- Average payment time: 1.2s
- Error rate: 0.1%

### During Incident
- Payment success rate: 0%
- All payments failing
- Error rate: 100%

### After Resolution
- Payment success rate: 99.9%
- Average payment time: 1.2s
- Error rate: 0.1%

## Follow-up

- [ ] Share post-mortem with company (Jan 20)
- [ ] Present learnings at engineering all-hands (Jan 25)
- [ ] Update incident response procedures (Jan 30)
- [ ] Schedule 30-day review of action items (Feb 15)

Incident resolved → Gather data → Schedule post-mortem meeting

Author writes initial draft → Include timeline and impact

Team reviews → Add perspectives → Refine action items

Finalize document → Share with stakeholders → Track action items

Review in 30 days → Verify actions completed → Share learnings