I built a recommendation engine: http://github.com/causes/suggestomatic http://github.com/causes/suggestomatic Because of the scale of data I'm using, I'm acut

I built a recommendation engine: http://github.com/causes/suggestomatic http://github.com/causes/suggestomatic Because of the scale of data I'm using, I'm acutely aware of big-O. I guess what's most interesting is that gcc is able to take some of those "slow" operations and make them super fast (if it can fit them in a register) and other times I get the full O(n) effect. Valgrind has been a very useful tool, and can empirically show you where your program is going to blow up (if you doubt your big-O analysis).