Deployment system

How this question breaks down

1. 1ArtifactsCore23 minTurn every merged commit into one immutable, signed artifact named by its hash, promote those same bytes from staging to production, and get them onto thousands of hosts in seconds.
2. 2RolloutsCore24 minTake one artifact from a small canary group to every host in waves sized by blast radius, replacing a few instances at a time so capacity holds and no request is dropped.
3. 3RollbacksCore24 minLet automated checks compare the new version with the old at every wave, halt and roll back within minutes when it is worse, and design changes so that going back is always safe.

Work through the parts in order and you’ve covered the full design. Each part is one topic.