A very good read here from game programming legend John Carmack.

In real­ity in com­puter sci­ence, just about the only thing that’s really sci­ence is when you’re talk­ing about algo­rithms. And opti­miza­tion is an engi­neer­ing. But those don’t actu­ally occupy that much of the total time spent pro­gram­ming. You know, we have a few pro­gram­mers that spend a lot of time on opti­miz­ing and some of the select­ing of algo­rithms on there, but 90% of the pro­gram­mers are doing pro­gram­ming work to make things hap­pen. And when I start to look at what’s really hap­pen­ing in all of these, there really is no sci­ence and engi­neer­ing and objec­tiv­ity to most of these tasks. You know, one of the pro­gram­mers actu­ally says that he does a lot of mon­key programming—you know beat­ing on things and mak­ing stuff hap­pen. And I, you know we like to think that we can be smart engi­neers about this, that there are objec­tive ways to make good soft­ware, but as I’ve been look­ing at this more and more, it’s been strik­ing to me how much that really isn’t the case.

The whole post is worth a read.