The good version of it is to only allow interacting with the environment declaratively (preferably idempotently as well), and then checkpointing those.

So rather than saying “open chrome, go to this page, click next page 5 times”, it would be something like “chrome is running; url is X; url is X/page/1; url is X/page/2” etc. Ansible, basically.

Other than that, you could just replay bash tool calls. That’s full of holes, though. Anything that relies on “date” will return different stuff, and if you try checkpointing the system time then TLS breaks due to timestamp differences.

If you wanted to go absolutely wild, some hypervisors can checkpoint the memory of a running VM and revert back to a prior version memory and all. I can’t imagine a way to make money off that (you’d be writing gigs of data per checkpoint), but I suppose it’s technically possible.