I spent two 12 month periods working exactly 17 hours a week (German paternity leave is incredibly progressive). Both times, it worked. When I tried tracking v

I spent two 12 month periods working exactly 17 hours a week (German paternity leave is incredibly progressive). Both times, it worked. When I tried tracking various arbitrary metrics of effectiveness (bugs fixed, commits made, files touched etc.) I found no real difference to working full-time. I also spent one month working one day a week. During that month my effectiveness also stayed roughly constant, although I sacrificed almost everything that wasn't communication or coding for that month. My focus during the working times was much higher. I never wasted time writing HN comments when I only had 4 hours to get my work done. It was also more stressful than working full-time. Everyone else in the company still spent 35 hours a week generating email and commit traffic, which meant I felt I was always playing catch-up with that aspect. I'd be interested to see what it's like when everyone in the company works a 4 day week.