Field Notes from a Rollback That Restored the Wrong Version

Under incident pressure the team rolled back to the previous deploy, which contained the same bug, because the last known good version was three deploys earlier.

Previous and good are different properties, and under pressure the team reached for the one that was easy to compute. The bug had shipped three deploys ago; the rollback restored it faithfully.

How targeting changed

• A last-known-good pointer updates only after verification passes.
• Rollback tooling defaults to known-good and warns on anything else.
• Verification windows are long enough to catch slow-burn defects.

Use the changelog, architecture guide, and audit schema to roll back to verified-good, not to whatever came before.