Thanks! Many of your issues sound more agent / LLM specific than LLMs in general. At least compared to my experiences.

It also aligns with what I saw from Claude & Claude Code when I used it last year for a while. Now I use Codex and don't see (nearly) as much of that sort of behavior.

> But LLMs seem to have a hard time getting the big picture and reusing code that is already implemented and ALMOST does what you want vs. rewriting everything from scratch.

Yeah that's probably the weakest point of LLMs still. GPT-5.6 Sol got much better at this for me. I still usually end up doing 2-3 iterations of prompts and exploration to clean up various things but usually it's pretty light work now.

> hundred of thousands of lines of documentation written as walls of text in markdown and weird coding decisions, your codebase is impossible to work out for a human.

Okay Claude definitely seems to have an issue there. From what I've seen from coworkers using Claude it generates reams of endless docs. I resist the urge to `rm docs/planning*.md`! I don't think they get how bad Claude is at that.

A month back I tried the latest DeekSeek and it made reams of text back and forth with itself, but the code it output was reasonable and it didn't make pages of markdown files either.

> I make it build things in small changes, I give very specific instructions about the architecture, and I make sure to point out existing functionality that can be used instead of writing something from scratch.

That's a bummer. I found that once the models start having problems that it cascades.

I've also been able to keep steady progress on a 70k+ LOC GUI side project without the endless whack-a-mole of bugs using Codex and Sol. Squash a bug, review architecture, move on, etc.