Ward Cunningham coined the term technical debt as a metaphor for the trade-off between writing clean code at higher cost and delayed de livery, and writing messy code cheap and fast at the cost of higher maintenance efforts once it's shipped. Joshua Kerievsky extended the metaphor to architecture and design. Technical debt is similar to financial debt: it supports quick development at the cost of compound interest to be paid later. The longer we wait to garden our design and code, the larger the amount of interest. Discussions of the metaphor have distinguished different types of technical debt and how and when to best pay them off. Most agree that, sooner or later, technical debt will come due. But is this assumption universally true? If it's better to pay interest, what factors influence the decision to service the debt? And if we decide to retire it, what approach should we take?