Something I wish someone had told me five years earlier:

LinkedIn Draft — Insight (2026-04-03) Something I wish someone had told me five years earlier: Zero-downtime deployments: what 'zero' actually requires most teams don't have Most teams say they do zero-downtime deploys and mean 'we haven't gotten a complaint in a while.' Actually measuring it reveals the truth: connection drops, in-flight request failures, and cache invalidation spikes during rollouts that nobody's tracking because nobody defined what zero means. What 'zero downtime' actually requires: ✓ Health checks reflect REAL readiness (not just 'process started') ✓ Graceful shutdown drains in-flight requests (SIGTERM handling) ✓ Connection draining at the load balancer (not just the pod) ✓ Rollback faster than the deploy (< 5 min, automated) ✓ SLI measurement during the rollout window (not just after) Missing any one of these = not zero downtime. Just unmonitored downtime. The non-obvious part: → The most common failure mode is passing health checks before the app is actually