Meaning
Reverting a software deployment or database transaction to a previously working version when a failure occurs.
Three examples from work
Production outage
LeadThe new release caused latency spikes across all API nodes.
DevOpsInitiating an immediate rollback to version 2.4.1.
Database migration
DevDid you write a rollback script for this schema migration?
LeadAlways. If the column rename fails, the down migration restores it.
Retrospective
PMHow fast was our rollback when the billing bug was detected?
DevOpsUnder ninety seconds thanks to our containerized blue-green deployment.
Can be used as a noun ('execute a rollback') or a phrasal verb ('roll back the deployment'). Have a tested rollback procedure before shipping major changes.