Interesting and semi-related idea: use LLMs to flag when comments/docs have come out of sync with the code.
The big problem with documentation is that if it was accurate when it was written, it's just a matter of time before it goes stale compared to the code it's documenting. And while compilers can tell you if your types and your implementation have come out of sync, before now there's been nothing automated that can check whether your comments are still telling the truth.
Somebody could make a startup out of this.
I once had a mad idea of creating an automated documentation-driven paradigm where every directory/module/class/function has to have a DocString/JSDoc, with the higher level ones (directory/module) essentially being the documentation of features and architecture. A ticket starts by someone opening a PR with suggested changes to the docs, the idea being that a non-technical person like a PM or tester could do it. The PR then passes to a dev who changes the code to match the doc changes. Before merging, the tool shows the doc next to every modified piece of code and the reviewer must explicitly check a box to say it's still valid. And docstrings would be able to link to other docstrings, so you could find out what other bits of code are connected to what you're working on (as that link doesn't always exist in code, e.g. across APIs) and read their docs to find the larger context and gotchas.
There is at least one startup doing it already (I'm not affiliated with it in any way): https://promptless.ai/
Why would you need comments from an AI if you can just ask it what the code is doing?
If you have CI hooked up to AI you could you just use a SLM to do that in a periodic job with https://github.github.com/gh-aw/ or https://www.continue.dev/. You could also have it detect architectural drift.
I'm a technical writer. Off the top of my head I reckon at least 10 startups have … started up … in this space since 2023.