Shipping Frontends with Zero Downtime: A Blue-Green Story

Most deploy downtime hides in a single gap: the moment between 'the new version started' and 'the new version is actually healthy'. Update an environment in place and your users live in that gap.

Blue-Green closes it. You keep the current version (Blue) serving 100% of traffic while the next version (Green) deploys to a warm, idle environment. Only after Green passes health checks does the load balancer switch traffic to it.

The quiet superpower is rollback. If something looks wrong, you don't redeploy — you point traffic back at Blue, which is still warm. Reversion is a switch, not a build, so it takes seconds.

Once frontend releases stopped causing error spikes, the team started shipping during the day instead of hiding deploys at midnight. That's the real win: reliability that changes how people work.