>I can manage about 3-4 hours of concentrated problem-solving a day at work. >In the evenings I sometimes don't have enough mental energy Here's my solution:

>I can manage about 3-4 hours of concentrated problem-solving a day at work. >In the evenings I sometimes don't have enough mental energy Here's my solution: Take your most valuable hours for yourself. Work in the morning and sell your less valuable hours. Is your employer going to notice? Extremely likely not. I am sure your job isn't just heads-down code monkey and involves meetings and other planning that aren't as draining.