Definition
A Rollback Plan is a documented, tested procedure for reversing a change if it doesn't go as expected, restoring a system to its previous working state.
Importance
Even a well tested change can behave unexpectedly once it reaches production, and without a rollback plan already prepared, the response to an unexpected problem becomes improvised under pressure, which is when mistakes compound rather than get contained. Having a tested, ready to execute rollback plan turns a potential extended outage into a quick, controlled recovery.
Application
We prepare and test rollback plans as a standard part of any significant deployment, cutover, or infrastructure change, rather than assuming a rollback will be straightforward to improvise if needed. This includes verifying the rollback procedure actually works before it's needed, since an untested rollback plan can fail at exactly the moment it's relied upon, which defeats the purpose of having one prepared in the first place.
