I believe you're trying to achieve what's impossible for most people. To have brain cycles left for mentally demanding side projects is not possible after 8 hrs

I believe you're trying to achieve what's impossible for most people. To have brain cycles left for mentally demanding side projects is not possible after 8 hrs solid coding work, for most people. Doing hard physical exercise for best part of an hour at some point in the day can revitalise and give , possibly counter-intuitively, more energy. That's a hack that helps a bit and is worth doing anyway. Other than that, how about ask to go 4 days a week, and spend the 5th on your side projects? That'd be a 20% salary hit , which is worth it if you can afford that and it either eventually pays itself back from side projects earnings or makes you happier and more fulfilled. Personally, I have some research ideas that I half fancy doing a Phd on one day, and I plan to do that once retired or semi-retired, so when 'm quite old. It wouldn't be realistic to try to do that before then on top of everything else. Another thing you could do of course is save up, take 6 months off and do all that on side project. But may require living frugally, and may be risky in current job market. Good luck :)