Exactly. I picked up some legacy invoicing code that's 13 years old, and people are terrified of breaking it, so it's just quietly rotted away and half of it is

Exactly. I picked up some legacy invoicing code that's 13 years old, and people are terrified of breaking it, so it's just quietly rotted away and half of it isn't even used anymore, but no-one can quite tell which half. First thing I did was add tests so that I can refactor with confidence.