> "don't touch it except to add things, you have no idea what depends on that chunk of code" To me that's just a symptom of a system that lacks good test cover

> "don't touch it except to add things, you have no idea what depends on that chunk of code" To me that's just a symptom of a system that lacks good test coverage. Being able to remove things that you believe to be unused and seeing if it's safe or not is one of the biggest benefits of test coverage. That and, of course, knowing if your "fix" doesn't break things far away that depend on it.