nw-deployment-strategies

# Deployment Strategies — Rollback, Risk, and Validation

For deployment strategy patterns (canary, blue-green, rolling, progressive delivery), see `cicd-and-deployment` skill. This skill focuses on operational concerns: validation, rollback, risk, and post-deployment.

## Pre-Deployment Validation

Before any deployment, validate:
- Deployment scripts tested in staging | Database migrations tested with rollback scripts
- Configuration management consistent across environments | Health checks and service discovery configured
- Monitoring and alerting systems prepared | Backup and disaster recovery procedures validated

## Rollback Procedures

### Design Rollback First
Every deployment plan starts with the rollback section:
1. **Database rollback**: migration revert scripts tested and verified
2. **Application rollback**: previous version tagged and deployable
3. **Configuration rollback**: previous config snapshots available
4. **Traffic rollback**: load balancer / feature flag kill switch ready
5. **Data rollback**: data consistency plan for partial rollback scenarios

### Automated Rollback Triggers
Configure automatic rollback when:
- Error rate exceeds baseline by >2x | P95 latency exceeds SLA threshold
- Health check failures exceed threshold (e.g., 3 consecutive) | Business metric anomaly detected (e.g., conversion drop >10%)

### Manual Rollback Decision Criteria
Stakeholder-reported functional issues | Security vulnerability discovered post-deploy | Data integrity concerns | Performance degradation below acceptable levels.

## Risk Assessment

### Technical Risks
Integration failure with downstream services | Performance degradation under production load | Data migration integrity issues | Security vulnerabilities introduced.

### Business Risks
User adoption challenges | Business process disruption | Stakeholder expectation misalignment.

### Operational Risks
Infrastructure capacity limitations | Third-party dependency failures | Team availability for incident response.

### Risk Mitigation Checklist
- [ ] Rollback procedure designed and tested
- [ ] Monitoring dashboards configured for deployment
- [ ] On-call team notified of deployment window
- [ ] Feature flags configured for gradual rollout
- [ ] Communication plan for stakeholders prepared
- [ ] Incident response runbook updated

## Post-Deployment Validation

### Production Smoke Tests
Critical user paths validated | Integration points tested with real external systems | Performance validated under production load | Security controls verified | Data integrity confirmed.

### Monitoring Validation
Application performance metrics collecting | Error tracking and alerting active | Business metric dashboards updated | Infrastructure monitoring nominal.