'We'll fix it later' is a loan. Here's the interest rate

Every time someone on your team says "we'll clean it up later," they're taking out a loan. The problem is that almost nobody checks the interest rate — until it bankrupts an entire sprint. Technical debt is the most-used and least-understood metaphor in software. Used well, the metaphor is genuinely powerful, because debt is exactly the right mental model — including the part everyone forgets: interest. Debt isn't the same as bad code First, a correction. Technical debt isn't just messy or bad code. It's a deliberate or accidental trade: you took a shortcut — skipped the abstraction, hardcoded the value, deferred the test — to move faster now, in exchange for a cost later. Sometimes that's a smart, conscious decision. Shipping today to validate an idea, knowing you'll refactor if it works, is often the right call. The debt isn't the problem; unmanaged, invisible debt is. The interest is the point Here's what the metaphor gets exactly right and most teams ignore. Debt accrues interest . Every feature you build on top of a shortcut is a little harder to build. Every bug in the messy area takes a little longer to fix. The shortcut doesn't cost you once — it taxes every future change that touches it, and that tax compounds. This is why teams mysteriously slow down over time. It rarely feels like a wall; it feels like everything gradually getting harder, estimates creeping up, small changes turning into week-long ordeals. That's compounding interest on debt nobody tracked. I've watched a system's velocity get quietly reclaimed by exactly this, and paying it down deliberately is part of how I approach building things properly . Good debt, bad debt The framework that makes this actionable: Deliberate, prudent debt: "We know the right design, but we're shipping the simple version to hit the deadline, and we'll fix it." Fine — it's a conscious, tracked trade. Accidental, reckless debt: "What's a design pattern?" — debt taken on through inexperience, invisibly, with no plan t