I've been reading comments by people who are hand optimizing for speed (or they object to things like encapsulation because of—often imagined—speed hits). With the obvious exceptions (e.g. real-time gaming), why does speed matter much? Of course, you don't want to be deliberately sloppy (e.g. function calls that return the same value inside of loops), my experience is that maintainabiity is more important than raw speed in most programs. If people aren't complaining about the speed, and if the cost of running cloud instances isn't more than the cost of maintenance, I see little point in optimizing for it.