If you're afraid to change something it is clearly poorly designed.

Comprehensiveness is the enemy of comprehensibility.

Any fool can write code that a computer can understand. Good programmers write code that humans can understand.

When you actually sit down to write some code, you learn things that you didn't get from thinking about them in modeling terms...there is a feedback process there that you can only really get at from executing some things and seeing what works

When to use iterative development? You should use iterative development only on projects that you want to succeed.

Why is composing symphonies tough? I don't know. It's just very few people in the world can do it well. And I think that's the case with upfront design. It is very hard to do well.

I find that writing unit tests actually increases my programming speed