I totally agree that tests aren't a replacement for thoughtful design, but neither is thoughtful design a replacement for tests. Thoughtful design can greatly

I totally agree that tests aren't a replacement for thoughtful design, but neither is thoughtful design a replacement for tests. Thoughtful design can greatly reduce the number of tests you need by reducing the complexity of your software and moving things to compiler-verified declarations. It can also prevent bugs by the sheer virtue of readability. This is not emphasized in the industry nearly as strongly as it needs to be.