Andrew Stellman at Building Better Software – Using nonfunctional requirements to build better software:
"One of those senior architects I mentioned gave me a really good tip recently, one that really rings true. He told me, “Always think about performance from day one of your project, and test for it until you deliver.”
[…] I like the fact that he’s thinking about how well the software works from the beginning of the project.
[…] The other thing I like is that he didn’t say, “Think about performance, scalability, usability, robustness, etc., from the beginning of the project.” He narrowed it down to the single quality attribute that was most important to his particular project."