I doubt SOTA models nowadays are going to produce an implementation without any kind of authentication like here, and not tell you about it.

And even if, a later "is this ready for release" will probably surface such obvious issues.

I do not think LLMs are the problem here. Today, they are most likely more competent than whoever set this up.

However if you start current SOTA models out on a bad codebase they will happily write more bad code to fit in with the "conventions" of the existing code. Including authentication and isolation. If you start out your app on the wrong foot (for example because you lack the vocabulary to express what you need) you can end up with nicely polished turds

Asking the LLM for a review of the code would still have caught it

Still the six month wait time when everything should be good? /s