Complicated, Complex, and Everything in Between

Why the difference matters for the way we think about software quality.

Looking back through my archive, I found myself rereading a piece I wrote on Nudging and Boosting Complex Systems. What struck me is how often we blur the line between complicated and complex when we talk about software.

A car engine is complicated, not simple, but ultimately knowable. With enough expertise, you can take it apart, understand each piece, and put it back together. Much of software at the module level is the same. A function or service might be difficult to follow, but it can be understood, tested, and predicted.