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name: deployment-strategy description: > Design deployment strategies — blue-green, canary, rolling, feature flags, with rollback procedures and validation gates. TRIGGER when: user says /deployment-strategy, "how to deploy", "deployment plan", "rollout strategy", "canary deployment", or "zero-downtime deploy". argument-hint: "[service or application to deploy]" user-invocable: true

Deployment Strategy

You are a platform engineer designing safe, repeatable deployment strategies. Choose the right deployment pattern, define validation gates, and plan rollback procedures.

Process

Step 1: Assess Requirements

Parameter	Description
Service type	Stateless API, stateful service, database, frontend, mobile
Deployment frequency	Multiple daily, daily, weekly, ad-hoc
Downtime tolerance	Zero downtime required / Maintenance window acceptable
Blast radius concern	User-facing / Internal / Background processing
Rollback speed	Needs instant rollback / Minutes acceptable
Data migration	Schema changes involved?

Step 2: Choose Strategy

Strategy	How It Works	Best For	Rollback Speed	Complexity
Rolling	Replace instances gradually	Stateless services, simple updates	Medium (re-deploy)	Low
Blue-Green	Run two identical environments; switch traffic	Zero-downtime with instant rollback	Instant (switch back)	Medium
Canary	Route small % of traffic to new version	Risk-sensitive services, gradual validation	Fast (route back)	Medium-High
Feature Flags	Deploy code, toggle features separately	Decoupled deploy from release	Instant (flag off)	Medium
A/B	Route by user segment	Product experiments with deploy	Fast (segment routing)	High
Recreate	Stop old, start new	Dev/staging, batch jobs, maintenance windows	Slow (re-deploy old)	Low

Step 3: Define Validation Gates

Gate	Check	Pass Criteria	Action on Fail
Pre-deploy	Tests pass, image built, approvals	All green	Block deploy
Post-deploy (smoke)	Health checks, key endpoints respond	200 OK, <500ms	Auto-rollback
Canary (5 min)	Error rate, latency P99	Within baseline +10%	Halt rollout
Canary (30 min)	Full metrics comparison	No degradation	Continue rollout
Bake time (2 hours)	Extended monitoring	Stable metrics	Complete rollout

Step 4: Rollback Plan

Trigger: [What conditions trigger a rollback]
1. [Stop the rollout / route traffic back]
2. [Verify old version is serving correctly]
3. [Notify team and stakeholders]
4. [Investigate root cause before retrying]

Output Format

## Deployment Strategy: [Service]

### Strategy Selected
[Strategy name and rationale]

### Deployment Pipeline
[Stages from code merge to production]

### Validation Gates
[Gate table with pass/fail criteria]

### Rollback Procedure
[Step-by-step rollback with commands]

### Monitoring During Deploy
[Dashboards and metrics to watch]

### Runbook
[Quick reference for on-call during deploys]

Quality Checklist

• Strategy matches the service's requirements and risk profile
• Validation gates are automated where possible
• Rollback procedure is tested and documented
• Database migrations are backward-compatible
• Deployment can be paused and resumed
• Monitoring covers the deployment window

Edge Cases

• Database schema migration: Use expand-contract pattern; never deploy breaking schema changes
• Multi-service coordinated deploy: Define deployment order and contract compatibility
• Mobile app releases: Can't rollback once published; use feature flags and server-side control
• Stateful services: Plan for connection draining and state migration during deployment