I don't believe in that tradeoff, at least from my experience with "business reports". When programs take a long time to run, they take also take a long time t

I don't believe in that tradeoff, at least from my experience with "business reports". When programs take a long time to run, they take also take a long time to debug. Your edit-run-test cycle is longer. In my experience, programs that are unnecessarily slow are often also unnecessarily buggy. The main reason is that developers don't want to touch them. They rot in the background while the underlying data changes. I'm talking about reports that take hours to run and often don't have any tests. It's pretty easy to get 10x improvement on such programs. This doesn't conflict with the notion that most programs (particularly business reports) don't need to be optimized at all. They just need to be written with some basic understanding of the problem and the underlying platform. Tests go a long way too.