I don’t mind working fulltime or overtime when the duty calls, but my professional sanity levels drop quickly after 4-5 hours a day, even if I want to do things. Sometimes faster. Some mornings I don’t even feel to care, and arrive only after noon (my superiors know that, I’m not lying to them). I also have observed and discussed it with other people, including management, and they agree that there is no reason to push developers to the limit in “peaceful” times, because 1) these reservoirs aren’t endless, 2) sometimes it’s better to just slack off than to hackathon yet another bullshit solution for a problem. Just go and sleep on it, you know. I also know a guy from mid-management of a huge local company and he said that even planned allocation in busy departments barely exceeds 40% (3+ hours/day) and bragged that he could bring it up to around 60%. I think they definitely have people who just do nothing on a daily basis, or report things like “I rotated keys in two servers yesterday, three more to go”, because nobody really knows anymore what that operation comprises.
Most of us developers and our managers perfectly understand that it’s not a paper-turning job and they really have no better options out there. In practice there is no supermen, only idiots who break things eventually in various ways. (Sorry if you, reader, are a rockstar developer. Nothing personal, but I’m tired to clean out these Augean stables)
The only exception is the flow, when I can shut the door and code straight through a day in a field that is completely my competence.