What you need to know
A rollback is only useful if the previous application version still works with the current database and assets. Data changes can make an old build incompatible even when code deployment is reversible.
How to apply it
Keep versioned deployments, back up critical data, document the rollback trigger, and practice restoring a copy in a safe environment. Separate reversible code changes from destructive data cleanup.
Common mistake to avoid
Do not assume a hosting platform rollback also restores database contents. Plan those recovery steps independently.