Branch computers like Git branches code

You're about to run a destructive migration on your dev database. Or upgrade Postgres major versions. Or let an AI agent loose on your filesystem. Or test what happens when you rm -rf the wrong directory.

You take a snapshot. It captures the entire container: files, processes, open ports, in-memory state of long-running services. You run the experiment. If it works, you keep the new state. If it doesn't, you restore the snapshot in 30 seconds and you're back to before.

Snapshots aren't backups. They're branches. You can run two experiments in parallel from the same snapshot, in two different containers, and pick whichever one ends up better. You can have a dozen "what if" branches of your environment running at once, costing nothing while idle.