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Ask HN: How are you LLM-coding in an established code base?

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11–20 of 69 posts

Re: Ask HN: How are you LLM-coding in an established code base?

#11
I would be very curious to hear about the state of your codebase a year from now. My impression was that LLMs are not yet robust enough to produce quality, maintainable code when let loose like this. But it sounds like you are already having more success than I would have guessed would be possible with current models.

One practical question: presumably your codebase is much larger than an LLM's context window. How do you handle this? Don't the LLMs need certain files in context in order to handle most PRs? E.g. in order to avoid duplicating code or writing something in a way that's incompatible with how it will be used upstream.

Re: Ask HN: How are you LLM-coding in an established code base?

#12
We're not. At ardour.org we've banned any and all LLM-generated code (defined as code that was either acknowledged to be LLM-generated or makes us feel that it was).

This is based on continual (though occasional) experiments asking various LLMs for solutions to actual known problems with our code, and utter despair at the deluge of shit that it produces (which you wouldn't recognize as shit unless you knew our existing codebase well). 2 weeks ago, there was the claim that our code makes extensive use of boost::intrusive_ptr ... in 300k lines of C++, there isn't a single use of this type, other than in an experimental branch from 6-7 years ago.

So we just say no.

Re: Ask HN: How are you LLM-coding in an established code base?

#14
> AFAICT, there’s no service that lets me: give a prompt, write the code, spin up all this infra, run Playwright, handle database migrations, and let me manually poke at the system. We approximate this with GitHub Actions, but that doesn’t help with manual verification or DB work.

What you want is CI/CD that deploys to rotating stating or dev environments per PR before code is merged.

If deployment fails you do not allow the PR to be approved. Did this for a primarily React project we had before but you can do all your projects, you just need temporary environments that rotate per PR.

Re: Ask HN: How are you LLM-coding in an established code base?

#15
> AFAICT, there’s no service that lets me: give a prompt, write the code, spin up all this infra, run Playwright, handle database migrations, and let me manually poke at the system. We approximate this with GitHub Actions, but that doesn’t help with manual verification or DB work.

I think this is almost exactly what we've built with https://superconductor.dev

- set up a project with one or more repos

- set up your environment any way you want, including using docker containers

- run any number of Claude Code, Codex, Gemini, Amp, or OpenCode agents on a prompt, or "ticket" (we can add Cursor CLI also)

- each ticket implementation has a fully running "app preview", which you can use just like you use your locally running setup. your running web app is even shown in a pane right next to chat and diff

- chat with the agent inside of a ticket implementation, and when you're happy, submit to github

(agents can even take screenshots)

happy to onboard you if that sounds interesting, just ping me at sergey@superconductor.dev

Re: Ask HN: How are you LLM-coding in an established code base?

#16

I use AI to write specific types of unit tests, that would be extremely tedious to write by hand, but are easy to verify for correctness. That aside, it's pretty much useless. Context windows are never big enough to encompass anything that isn't a toy project, and/or the costs build up fast, and/or the project is legacy with many obscure concurrently moving parts which the AI isn't able to correctly understand, and/o…

My experience is very similar.

For greenfield side projects and self contained tasks LLMs deeply impress me. But my day job is maintaining messy legacy code which breaks because of weird interactions across a large codebase. LLMs are worse than useless for this. It takes a mental model of how different parts of the codebase interact to work successfully and they just don't do that.

People talk about automating code review but the bugs I worry about can't be understood by an LLM. I don't need more comments based on surface level patter recognition, I need someone who deeply understands the threading model of the app to point out the subtle race condition in my code.

Tests, however, are self-contained and lower stakes, so it can certainly save time there.

Re: Ask HN: How are you LLM-coding in an established code base?

#17
I don't "vibe code", but I do two main things:

1) I throw it the simpler tasks that I know only involve a few files and there are similar examples it can work from (and I tend to provide the files I'm expecting will be changed as context). Like, "Ok, I just created a new feature, go ahead and setup all test files for me with all the standard boilerplate. Then I review, make adjustments myself (or re-roll if I forgot to specify something important), then commit and move forward.

2) I use the frontier thinking models for planning help. Like when I'm sketching out a feature and I think I know what will need to be changed, but giving, say, an Opus 4.5 agent a chance to take in the changes I want, perform searches, and then write up its own plan has been helpful in making sure I'm not missing things. Then I work from those tasks.

I agree that Copilot's Cloud agents aren't useful (they don't use smart models, presumably because it's $$$) and also I'm not a great multitasker so having background agents on worktrees would confuse the heck out of me.

Re: Ask HN: How are you LLM-coding in an established code base?

#19

We're not. At ardour.org we've banned any and all LLM-generated code (defined as code that was either acknowledged to be LLM-generated or makes us feel that it was). This is based on continual (though occasional) experiments asking various LLMs for solutions to actual known problems with our code, and utter despair at the deluge of shit that it produces (which you wouldn't recognize as shit unless you knew our existi…

How do you review the no?

Re: Ask HN: How are you LLM-coding in an established code base?

#20

I generally vibe code with vim and my playlist in Cmus.

Man I was vim for life until cursor and the LLMs. For personal stuff I still do claude + vim because I love vim. I literally met my wife because I had a vim shirt on and she was an emacs user.

Claude open in another tab, hitting L to reload the file doesn't do it for you?
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