How zero-downtime deploys work

Blue-green cutovers, health checks, previews, and rollbacks on cloud hosting.

Preview first

Every change should land on a preview URL that mirrors production. Share that link for QA before promoting.

Cutover

Production builds a new release beside the live one. Traffic switches only after health checks pass.

Health checks

We probe critical routes — not just the homepage. Failed checks cancel cutover and keep the previous version live.

Rollback

Roll back from deploy history to any healthy prior release. Rollback is a traffic shift, not a full rebuild.

Deep dive: Zero-downtime deploys with preview environments.

How zero-downtime deploys work — Build Me Web Help