When was the last time you heard the term "technical debt?" If you're a developer, it was probably pretty recently. Now when was the last time you heard the term "technical interest?" I bet it has been significantly longer. Ward Cunningham, who coined the term "technical debt," was definitely thinking about the interest angle: "Every minute spent on not-quite-right code," he wrote, "counts as interest on that debt." But I think a lot of developers and shops today aren't thinking about technical interest as a consequence of technical debt. They treat technical debt as a casual interest-free loan from friends or family--a "debt" that may never even come due. I think this attitude towards technical debt is a mistake. I think that we not only pay interest on our technical debt--we often pay vigorish.