source? I'm wondering at the curve of those mistakes actually, I doubt modern LLMs make mistakes at the level of the worst engineers I've worked with.

My last project had 2 guys from India and one guy from a consulting company that I take any LLM over them. The guy from the consulting company spent more than a month trying to implement a design that actually was not implementable. I obviously also blame the supposed professional design company that produced the design, and I mean it took me about 6 hours spread over a day and a half to figure out waitaminute this is actually not doable! But I have to wonder how badly would an LLM have done. I sort of think the same, because probably an LLM is never going to announce - hey, this design as stated is impossible, some parameter needs to be changed.