> At scale, even your bugs have users

Also known as ossification. It is a term most often heard in the context of network protocols, but it applies more generally to every system where users depend on unspecified behaviors and even bugs.

Reading about HTTP/3 and QUIC is interesting in that aspect. I first didn't understand the insistance on encryption. Turns out it is not just security and privacy, but by encrypting everything that is not strictly necessary for proper transport, you make it impossible for any "middlebox" to make assumptions they shouldn't make.

I think similar approaches can be used by APIs. Never expose more than what is specified, treat the ability to access internal state as a bug, not because it is secret, but because if users start relying on it, internal changes that shouldn't break anything will.

Similar to Hyrum 's Law for APIs