# What is a rollback, and why ask whether it has been tested?

A rollback is putting the previous working version back. It only counts if somebody has done it, because the first attempt always uncovers something: a migration that does not reverse, a cache holding the old shape, credentials nobody has. A rollback plan written down and never run is a hope with a procedure attached.

Also called: revert, staged rollout
Checked: 2026-09-27

In one line

Putting the last working version back, on a path somebody has walked.

## Why it matters to you

The cheapest version is the one that shares a path with ordinary work. On octyn.co, rollback is a revert and a push, which is the same path as any deploy, so there is no separate emergency procedure to get wrong under pressure. A build that does not compile never replaces the running container, so a broken commit leaves the live site untouched.

Mobile is different because the store is in the way, so Mooney rolls back through the Play staged rollout: a bad build halts at a percentage instead of being recalled.

The harder case is the data, which a code rollback cannot undo. If the system wrote something wrong to a database, going back to the old version does not unwrite it. That is why rollback questions should always be asked twice, once about the code and once about the rows.

## Where it turns up in something we run

- Rollback on octyn.co is a revert and a push, the same path as any deploy (recorded 2026-09-14, [octyn.co](https://octyn.co/casestudies/octyn-site))
- Mooney rolls back through the Play staged rollout, so a bad build halts at a percentage (recorded 2026-09-14, [Mooney](https://octyn.co/casestudies/mooney))

## Next to this

- [Observability](https://octyn.co/glossary/observability)
- [Dry run](https://octyn.co/glossary/dry-run)
- [Human in the loop](https://octyn.co/glossary/human-in-the-loop)

## Argued out at length

- [What production ready means for an AI system](https://octyn.co/compare/production-ready-ai-system)
- [What it costs to change an AI workflow six months later](https://octyn.co/compare/cost-to-change-ai-workflow-six-months)

## Related

- [What production ready means for an AI system](https://octyn.co/compare/production-ready-ai-system)
- [Observability](https://octyn.co/glossary/observability)
- [The Consult](https://octyn.co/consult)

Canonical: https://octyn.co/glossary/rollback