Ike: There's a difference between policies and mechanisms. The policies are your business logic, the mechanisms are how you go to ousel. Kim van wick out there says, fantastic advice about having too many, too much figure ability. I think that's very valuable. It's not enough to see it by example. Ike: You don't want to tonotisance shade the whole premature optimization is the root of all evil. But without that measurement, without that data, it’s a fruitless endeavor.