Which deployment strategy minimizes downtime by switching all traffic to a newly provisioned identical environment after validation?

• A. Canary deployment
• B. Rolling update
• C. Blue-green deployment
• D. Immutable infrastructure

Answer: (C)

Blue-green deployment is about minimizing downtime by having two identical production environments. One runs live traffic while you provision and validate the new version in the idle environment. When validation passes, you switch all traffic to the new environment with a single cutover through the load balancer or routing layer. Because the old environment is still intact and can be reactivated quickly, rollback is simple if something goes wrong. This approach contrasts with gradual methods that expose users to changes step by step, or with immutable infrastructure that emphasizes replacing components rather than swapping two full production environments.