All 4,799 reports

NoCursor · 7 Feb 2026

When the system requirements change, the LLM isn't removing old code, it's just adding new branches and keeping the dead code around

apical_dendrite on Hacker News

In the thread “LLMs as the new high level language”

Helped: One-shotting simple tasks like adding a page to a React app.

Got in the way: Refactoring complex legacy code; LLM adds branches instead of removing dead code.

… No unit tests, of course, so it's very difficult to tell if anything broke. When the system requirements change, the LLM isn't removing old code, it's just adding new branches and keeping the dead code around. I ask the developer the simplest questions, like "which of the multiple entry-points do you use to test this code locally", or "you have a 'mode' parameter here that determines which branch of the code executes, which of these modes are actually used? …