deployment-patterns

# Deployment Patterns Production deployment workflows and CI/CD best practices. ## When to Activate - Setting up CI/CD pipelines - Dockerizing an application - Planning deployment strategy (blue-green, canary, rolling) - Implementing health checks and readiness probes - Preparing for a production release - Configuring environment-specific settings ## Deployment Strategies ### Rolling Deployment (Default) Replace instances gradually: old and new versions run simultaneously during rollout. ``` Instance 1: v1 → v2 (update first) Instance 2: v1 (still running v1) Instance 3: v1 (still running v1) Instance 1: v2 Instance 2: v1 → v2 (update second) Instance 3: v1 Instance 1: v2 Instance 2: v2 Instance 3: v1 → v2 (update last) ``` **Pros:** Zero downtime, gradual rollout **Cons:** Two versions run simultaneously: requires backward-compatible changes **Use when:** Standard deployments, backward-compatible changes ### Blue-Green Deployment Run two identical environments. Switch traffic atomically. ``` Blue (v1) ← traffic Green (v2) idle, running new version # After verification: Blue (v1) idle (becomes standby) Green (v2) ← traffic ``` **Pros:** Instant rollback (switch back to blue), clean cutover **Cons:** Requires 2x infrastructure during deployment **Use when:** Critical services, zero-tolerance for issues ### Canary Deployment Route a small percentage of traffic to the new version first. ``` v1: 95% of traffic v2: 5% of traffic (canary) ...