The Faster We Build with AI, the More Dangerous Bad Auth Becomes - And the Rarer Good Auth Becomes

The Faster We Build with AI, the More Dangerous Bad Auth Becomes - And the Rarer Good Auth Becomes While everyone races to ship with AI, understanding authentication and authorization is quietly becoming the most valuable skill in backend engineering. Let me set a scene that probably sounds familiar. You're building a new backend service. You open Cursor, type a prompt - "implement OAuth 2.0 login with JWT tokens" - and in about 8 seconds you have 150 lines of clean, readable, production-looking code. You skim it. It looks right. You move on. I've done this. Most engineers I know have done this. And here's what nobody talks about: that code is often almost correct. Not obviously broken - just subtly, silently wrong in ways that don't surface until something goes wrong in production. A token that should expire doesn't. A user who should lose access still has it. An endpoint that should be protected isn't. The AI didn't fail you. You just didn't know what to check. That's what this post