It's quite an unpopular opinion, but it heavily depends on person.
When I was starting my startup, it was usually solid work from 9/10 to 22:00/ 23, 7 days a week. The big difference is, that in those moments, work was well diversified, so when I felt exhausted by creative part, I went to repetitive tasks, then to investigate how legal part works, then to emails etc. It's mostly about having a right tactics.
In current work, there are still people who think that boss will give them 20% more career progression, when they work 20% more than contractual hours. Being quite productive in areas they already know.
So it is possible but I don't believe it's most viable strategy. I prefer much more to work on personal coding projects after work, trying new methods, not on stuff I already know very well.
It may only be unpopular on Hacker News. I saw an engineering account poll their followers on Twitter and this kind of opinion was a tiny minority. I would most likely be finding a way to think eight hours a day even if I weren't at work.
In current work, there are still people who think that boss will give them 20% more career progression, when they work 20% more than contractual hours. Being quite productive in areas they already know.
So it is possible but I don't believe it's most viable strategy. I prefer much more to work on personal coding projects after work, trying new methods, not on stuff I already know very well.