Jonathan Blow has a good talk about this. He says when he interviews he wants somebody that will default to a naive implementation (because most code is not per

Jonathan Blow has a good talk about this. He says when he interviews he wants somebody that will default to a naive implementation (because most code is not performance-sensitive and you should optimize for development time in those cases), but he expects people to have a wide knowledge of tricks and techniques for the ~10% that is performance sensitive. That seems fair to me, as somebody who probably wouldn't pass his standards and needs to develop my algorithmic knowledge to handle that 10% better.