Blue-Green vs Canary vs Rolling: Decision

Three deployment strategies. The trade-offs and the team behaviour each rewards.

Blue-green

Two full environments; flip traffic atomically. Fast rollback (flip back).

Cost: double infrastructure during deploy.

Canary

Gradual rollout (5% → 25% → 50% → 100%). Catches issues early; harder to fully rollback.

Best for: applications where partial rollout is acceptable.

Rolling

Replace instances one at a time. Simple; standard in K8s.

Slow if many instances. Rollback is also rolling; not instant.