HN is weird about flagging. I'm a bit skeptical about the folks who flag things on this platform-- they are biased and may even have an agenda. Fortunately looks like my original reply has been unflagged.
That's fantastic about your personal research into the matter of length of time of sustained focus.
A notary is a publicly commissioned official who serves as an impartial witness to the signing of a legal document. Document signings where the services of a notary are likely include real estate deeds, affidavits, wills, trusts, and powers of attorney. The main reason a notary is used is to deter fraud."
I think 5 hours of 100% engaged, mentally intense work is about all that can be expected from a person in a day.
After 5-6 hours of mentally intense work, there are diminishing returns.
Therefore, I think about 6 hours/day are what should be expected from a developer, including 30-60 minutes of meetings/admin work. Though some companies might need another hour or two-- hopefully such extra time is not mentally intense and is more socially oriented work (such as meetings).
"Youtube: How Hard Should You Work? - Jordan Peterson"
Holy cow, this is absolutely fascinating. Figured it deserves more than just an upvote-- This speaker you linked mentions another fascinating talk within his lecture:
"1177 B.C.: When Civilization Collapsed | Eric Cline"
Operation Mockingbird is an alleged large-scale program of the United States Central Intelligence Agency (CIA) that began in the early years of the Cold War and attempted to manipulate news media for propaganda purposes.
That's fantastic about your personal research into the matter of length of time of sustained focus.