My yard stick is discoverability. If you don’t touch things for a while they get fuzzy, and someone might have refactored it. So you need to be able to familiar

My yard stick is discoverability. If you don’t touch things for a while they get fuzzy, and someone might have refactored it. So you need to be able to familiarize yourself with bits of the code you haven’t looked at recently. Helps with code reviews, onboarding, and production outages. In particular it’s difficult to train new people to take up on-call duties if they cannot sit in the corner of the room and try either the same things you’re trying or their own pet theories without taking your attention or interfering with your tests. They need to be able to hear the repro steps and spool up their own snapshot in a similar state. That scales. Gatekeepers do not. Discoverability is necessary but insufficient to achieve this. There’s more to it but the foundation is discoverability and reproduceability.