LLMs can really only mostly do trivial things still, they're always going to do very bad work outside of what your average web developer does day-to-day, and even those things aren't a slam dunk in many cases.
On the plus side, I got to see first-hand how Postgres handles deadlocks and read up on how to avoid them.
I'm not saying it's the hardest thing but I also wouldn't consider it trivial.