I’m glad to know that I’m not alone in thinking about Software Debt. Ward Cunningham has a great video up about it, which is starting to filter through the internets.
Maybe if we get people thinking about Software Debt a bit more, we can make the software world a bit more sane.
I’ve been thinking about a lot of things in terms of debt recently, and the world looks a bit different if you do that. Debt is borrowing against the future, be that in time, money, energy, health, etc. Debt is what you get when you take short cuts, as you are borrowing from the future.
When your debt is money, it’s somewhat easy to understand. You take money from the future you which you have to pay back at some point. It’s a little harder to understand in areas that aren’t money.
If you create a new piece of code you are creating both value and debt. Debt is created by taking shortcuts, as the software will need to be reworked to reasonably extend it in the future. You take a short cut now to pay for it later, with interest. Every future feature will take longer until you pay back your debt. Refactoring is really all about paying down debt in a responsible way in software.
Most of the time the right approach is to pay off your debt. The other option is bankruptcy (which we are seeing a lot of this week in the financial world). Software bankruptcy is throwing the whole thing out and starting from scratch.
When I started thinking about software development in terms of debt in the last few weeks, lots of things started to make a lot more sense. Shortcuts are debt. Inconsistent interfaces are debt. Inconsistent coding style is debt. Bad or wrong abstractions are debt. Missing documentation is debt. Confusing APIs are debt. If you want a project to move forward more productively you need to eliminate some of your debt, as it’s what slows people down (green field code is easy, brownfield is hard).
I’d love to hear about other concepts of debt, and what debt looks like in other media besides software. Please post comments if you are so inclined.