"Let it crash" is the BEAM's answer to failure: processes crash, supervisors restart them, and the system recovers. That confidence is earned, but some bugs hide behind it. They live in the gaps between processes, where getting things right is subtle and getting things wrong looks exactly like getting things right. You'd have to never blink to see them. Argus Panoptes was a hundred-eyed giant who never blinked. I named a tool after him and pointed it at libraries you use in production.