>You might be right that some people can be productive more than 40 hours per week because I am one of them.
Is that constant heads down, in the zone coding, or does that include some coding, some management, some marketing, etc? Also, how long can you do that for? 5 years straight?
I typically work in bursts. If I don't have an outlet in between bursts (surfing, 30 minute tv show, walk, etc), the longer it takes to get back into a burst. Being in an office doesn't offer much as far as outlets go.
It's the same for me, I work in bursts. Sometimes I will have 30m-1h of not very productive time (reading blog post on web, going for a walk etc) but then I will have a burst of productivity when I hunker down for couple of hours and do a lot of work.
Obviously it isn't constant 8 hours of heads down, in the zone coding, there are things in between and also meetings and planning often takes time. I used to work longer before but as you say, that is not sustainable for a long run, you can do it for couple of years before you burn out.
I also used to do quite a lot of extra work in the evenings and weekends when I had sudden inspiration / urge to refactor or improve some piece of code. But I don't do that anymore and instead use that free time for myself and my hobbies :)
If I feel an urge to write some code on Sunday, I will work on one of my open source projects or contribute to some other projects out there if they interest me or I will experiment with new tech to keep my skills up to date.
Is that constant heads down, in the zone coding, or does that include some coding, some management, some marketing, etc? Also, how long can you do that for? 5 years straight?
I typically work in bursts. If I don't have an outlet in between bursts (surfing, 30 minute tv show, walk, etc), the longer it takes to get back into a burst. Being in an office doesn't offer much as far as outlets go.