Every Mutation Needs an Undo

Every script that mutates system state should build an undo alongside the forward operation. The pressure to skip this is real. The forward path is the goal, the undo feels defensive. But when you need it, you need it immediately: under time pressure, during someone else’s incident, with adrenaline compromising your judgment. A hastily improvised undo under those conditions makes things worse.

The practical rule: every mutation script should log the exact commands needed to reverse its effects, even just printing inverse commands to stdout as the forward operations execute. The cost of building the undo is paid once; the cost of not having it is paid repeatedly and unpredictably.