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lacunarylast Wednesday at 12:49 AM5 repliesview on HN

in my experience, what happens is the code base starts to collapse under its own weight. it becomes impossible to fix one thing without breaking another. the coding agent fails to recognize the global scope of the problem and tries local fixes over and over. progress gets slower, new features cost more. all the same problems faced by an inexperienced developer on a greenfield project!

has your experience been otherwise?


Replies

ewoodrichlast Wednesday at 1:24 AM

Right, I am a daily user of agentic LLM tools and have this exact problem in one large project that has complex business logic externally dictated by real world requirements out of my control, and let's say, variable quality of legacy code.

I remember when Gemini Pro 3 was the latest hotness and I started to get FOMO seeing demos on X posted to HN showing it one shot-ing all sorts of impressive stuff. So I tried it out for a couple days in Gemini CLI/OpenCode and ran into the exact same pain points I was dealing with using CC/Codex.

Flashy one shot demos of greenfield prompts are a natural hype magnet so get lots of attention, but in my experience aren't particularly useful for evaluating value in complex, legacy projects with tightly bounded requirements that can't be easily reduced to a page or two of prose for a prompt.

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rectanglast Wednesday at 1:41 AM

Adding capacity to software engineering through LLMs is like adding lanes to a highway — all the new capacity will be utilized.

By getting the LLM to keep changes minimal I’m able to keep quality high while increasing velocity to the point where productivity is limited by my review bandwidth.

I do not fear competition from junior engineers or non-technical people wielding poorly-guided LLMs for sustained development. Nor for prototyping or one offs, for that matter — I’m confident about knowing what to ask for from the LLM and how to ask.

baqlast Wednesday at 6:29 AM

This is relatively easily fixed with increasing test coverage to near 100% and lifting critical components into model checker space; both approaches were prohibitively expensive before November. They’ll be accepted best practices by the summer.

multisportlast Wednesday at 4:12 PM

No that has certainly been my experience, but what is going to be the forcing function after a company decides it needs less engineers to go back to hiring?

tjrlast Wednesday at 1:05 AM

Why not have the LLM rewrite the entire codebase?