On the other had, a complex code base, that was done hackily in a few hours just to get to the solution without any thought for maintainability or has no test c

On the other had, a complex code base, that was done hackily in a few hours just to get to the solution without any thought for maintainability or has no test coverage, is technical debt, because the person 'borrowed' time amongst other things with the hacked up codebase... Yup, usually because some sales/marketing/managing idiot had to have something look nice at a show and then wonder why an engineer is wasting time stabilizing the code base before he can give it to a customer. "It worked at the show...WTF?"