The spec is as much for humans as it is the machine, yes?

Spec should be made before hand and agreed on by stakeholders. It says what it should do. So it’s for whoever is implementing, modifying, and/or testing the code. And unfortunately devs have a tendency of poor documentation

Software development is only 70ish years old and somehow we have already forgotten the very very first thing we learned.

"Just get bulletproof specs that everyone agrees on" is why waterfall style software development doesn't work.

Now suddenly that LLMs are doing the coding, everyone believes that changes?

I’m confused, are you saying that making a design plan and high level spec before hand doesn’t work?

I've seen it happen. Things that seem reasonable on a spec paper, then you go to implement and you realize it's contradictory or utter nonsense.

I mean yeah it happens all the time but you need to start somewhere. But I worked in safety critical self driving firmware and rtl verification before that, so documentation was a necessity