[muzani]

Working a proper 9-5 job in software is extremely tiring. I compare it to athletes; you can't expect an athlete to work 8 hours a day of intense training without collapsing. Often they work a certain amount of hard hours and a few softer ones. They cycle it.

One should do the same for programming as well. It's all energy management. I find I can only work 3 hours on a tough problem, and the rest would be something lighter like refactoring or writing tests.

A lot of people who wake up at 5 and sleep at 11 PM are managers, which isn't as energy intensive.