I go back and forth on whether the name “Tech Debt” is the most useful term. In my book, I decided I can’t fight the term, so I use it, but in my opening paragraphs I make an argument that the problem we call tech debt isn’t like other debt.
The most common way I’ve seen tech debt is that it’s just everywhere. It’s not limited to a specific old module, it pervades the codebase like marbleized fat in a good steak, but not as delicious.