There is such a thing as programming trance, with working 16hrs a day and very high productivity. But then, you need an environment fully devoid of distractions

There is such a thing as programming trance, with working 16hrs a day and very high productivity. But then, you need an environment fully devoid of distractions (like working from home if you are single or a locked personal office otherwise), no interactions with your boss or co-workers etc. Unlikely to happen in a company where long working hours are a norm. Also, programming trance can last at most a week and you can't do it more often than once or twice a year. There are physical limits to what your brain can sustain.