IMO 1. Make it correct and not insane asymptotically. 2. Tune constant factors, if you need to. In school I was confused why they kept on talking about asymp

IMO 1. Make it correct and not insane asymptotically. 2. Tune constant factors, if you need to. In school I was confused why they kept on talking about asymptotics and ignoring the different costs of the building blocks. Now I see that, while it is true that asymptotic analysis doesn't well explain performance when "things are good": 1. There are a lot of stupid things people do write that it does catch. 2. Since it is scale free, it makes sense as a way to evaluate programs throughout their entire development. 3. Constant factor optimizations will always tempt one to ruin abstraction boundaries, but asymptotic analysis shouldn't----or if it does, sorry your abstraction sucks and needs to go. (Hi ORMs.) The latter points are really powerful. Never make me work without efficient tree map/set union and intersection ever again.