Question

A cloud engineer must deploy a new version of a customer-facing web application with zero downtime. Requirements state that the new version must be fully tested in a production-identical environment before receiving live traffic, and that traffic must be able to revert instantly to the previous version if post-deployment validation fails. Which deployment strategy BEST meets these requirements?

Accepted Answer

Blue-green deployment, standing up the new version on a parallel environment and switching the load balancer once validation passes

Answer

Rolling deployment, replacing instances in the existing environment in small batches

Answer

In-place deployment, updating the application binaries on the running production servers

Answer

Canary deployment, gradually shifting a small percentage of live users to the new version over several hours