A team wants zero-downtime deployments where a new environment runs alongside the old, traffic shifts only when the new version is verified, and rollback is instant. Which deployment strategy is this?
A.In-place rolling deployment
Rolling replaces instances incrementally — no isolated full environment.
B.Blue/green deployment
Correct. Two parallel environments with an atomic traffic shift = blue/green.
C.Canary deployment to 10% then 100%
Canary is a gradual percentage ramp, not an all-at-once shift.
D.Recreate deployment
Recreate causes downtime while the old version is torn down.
Why this answer
Blue/green runs two full environments: traffic shifts wholesale from blue (old) to green (new) after verification, with instant rollback by shifting back. CodeDeploy supports this pattern for EC2 and ECS.
Correct answer: B · Last reviewed 2026-10-26
Official AWS references
Practice this interactively
Answer without seeing the solution first in the CI/CD & Observability practice session.
Practice CI/CD & Observability