codedeploy

ECS CodeDeploy and Lambda aliases support both instant cutover and gradual shifts—but picking wrong costs you double Fargate spend or 21-day MTTR on muted alarms. This decision guide scores blue/green, canary, and rolling with a matrix and names App Mesh (EOL Sept 30, 2026) replacements.

ECS blue/green without downtime: CodeDeploy canary/linear still works — and native ECS BLUE_GREEN (2025+) is now a first-class path. July 2026 checklist: hooks, alarms, dual-run cost.