I wonder if the OP's question is motivated by there being less public examples of COBOL code to train LLM's on compared to newer languages (so a different experience is expected), or something else. If the prior, it'd be interesting to see if having a language spec and a few examples leads to even better results from an LLM, since less examples could also mean less bad examples that deviate from the spec :)
if there are any dev's that use AI with COBOL and other more common languages, please share your comparative experience
Ask HN: COBOL devs, how are AI coding affecting your work?
11–20 of 190 posts
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#12I've not found it that great at programming in cobol, at least in comparison to its ability with other languages it seems to be noticeably worse, though we aren't using any models that were specifically trained on cobol. It is still useful for doing simple and tedious tasks, for example constructing a file layout based on info I fed it can be a time saver, otherwise I feel it's pretty limited by the necessary system specifics and really large context window needed to understand what is actually going on in these systems. I do really like being able to feed it a whole manual and let it act as a sort of advanced find. Working in a mainframe environment often requires looking for some obscure info, typically in a large PDF that's not always easy to find what you need, so this is pretty nice.
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#13I really wouldn't want any vibe-coded COBOL in my bank db/app logic...
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#14The point about the mass of code running the economy being untouched by AI agents is so real. During my years as a developer, I've often faced the skepticism surrounding automation technologies, especially when it comes to legacy languages like COBOL. There’s a perception that as AI becomes more capable, it might threaten specialized roles. However, I believe that the intricacies and context of legacy systems often require human insight that AI has yet to master fully.
I logged my fix for this here: https://thethinkdrop.blogspot.com/2026/01/agentic-automation...
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#15I really wouldn't want any vibe-coded COBOL in my bank db/app logic...
Does the use AI always implies slope and vibe coding? I’m really not sure
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#16I would assert this is affecting all programming languages, this is like the transition from Assembly to high level languages.
Who thinks otherwise, even if LLMs are still a bit dumb today, is fooling themselves.
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#17I see it as a complete opposite for sure, I will tell you why.
it could have been a threat if it was something you cannot control, but you can control it, you can learn to control it, and controlling it in the right direction would enable anyone to actually secure your position or even advance it.
And, about the COBOL, well i dont know what the heck this is.
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#18I really wouldn't want any vibe-coded COBOL in my bank db/app logic...
Does the use AI always implies slope and vibe coding? I’m really not sure
No, it doesn't. For example, you could use an AI agent just to aid you in code search and understanding or for filling out well specified functions which you then do QA on.
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#19I am in banking and it's fine we have some finetuned models to work with our code base. I think COBOL is a good language for LLM use. It's verbose and English like syntax aligns naturally with the way language models process text. Can't complain.
Can you elaborate? See questions about what kind of use in sibling thread.
And in addition to the type of development you are doing in COBOL, I'm wondering if you also have used LLMs to port existing code to (say) Java, C# or whatever is current in (presumably) banking?
Re: Ask HN: COBOL devs, how are AI coding affecting your work?
#20There was a COBOL LLM eval benchmark published a few years ago, looks like it hasn’t been maintained: https://github.com/zorse-project/COBOLEval
At least I think that’s the repo, there was an HN discussion at the time but the link is broken now: https://news.ycombinator.com/item?id=39873793