Backups

An enabled-bucket version stack has a delete marker above earlier data; a versionless GET is blocked with 404.

Bucket versioning and lifecycles manage cost

S3 Versioning retains multiple versions under one key, making many accidental overwrites and ordinary deletes recoverable while the required version still exists. It does not protect against every deletion or provide an independent backup by itself. Retention, permissions, encryption-key availability, and restoration procedures determine whether the saved history can actually recover the application. ...

Retrieve an archive and checksum from storage, verify the retrieved copy before use, and restore into an isolated disposable test target. Check files, permissions and elapsed restore time. A stored file alone is not proof of recovery.

Backups are only useful after a restore rehearsal

Choose a small recovery unit, verify it, and practice restoring it somewhere disposable.