Everyone is building at AI speed right now.
That is fine for most of the app. It is a terrible place to freestyle authentication.
A half-baked login looks "done" in a demo and fails under real users: broken sessions, weak password flows, MFA bolted on late, multi-tenant gaps, cookies that only work on localhost. The model will happily invent a sign-in form. It will not invent a security posture.
Because it stops you inventing the one surface that should never be improvised.
Clerk is an excellent Auth skill and for new SaaS, prototypes, and startups where speed-to-market is the metric and the stack is modern frontend. It is a poor tool when at consumer-scale unit economics are the product constraints.
This is not "never build auth." It is "do not invent the front door while the rest of the app is still a sketch."
The principle: Velocity is only a win if the you don try and speed run the boring bits.
//A<3