How many hours a day can you reliably do high difficulty cognitive work?

If the topic enthuses me, >12 hours. If it doesn't, 2 + long break + 2 is a max.

Advice 1: validate your assumptions. You seem to imply that maximising work hours maximises productivity. It could well be that you are above-average productive to start with, so you get more work done in a shorter amount of time. If that's the case, maybe you hit a limit that isn't mean to be passed.

Advice 2: validate your baseline. Are you in good shape and health? How does your productivity compare to peers? Are you working on harder topics than your peers? Is your work environment distraction-free? Is there something (health, personal life, financials etc) bothering you?

Advice 3: validate your motivation. Are you enthusiastic about the topic? If not, balance that against your goals and if you still think you need to do it, trick yourself into finding the work motivating [1].

Advice 4: experiment with different modes. I didn't know about the pomodoro technique before. After a short read, I don't think I would enjoy working like that. Breaking every half hour kills my flow, and 5 minute breaks are too short to get anything done.

[1] https://upload.wikimedia.org/wikipedia/en/a/ab/Simpsons6x13....

I’m a very productive very lazy developer. In younger years I used to stay up for three days straight programming or working out some infrastructure crisis (catching occasional cat naps on server room floors, meow.)

You must pace yourself. Dividing work by cognitive load helps. Intellectual work in the early hours, casual work in between, and finally “talk to people time.”

What you will eventually find, is that thought productivity ratios are non-linear. You will become a superior problem solver with the realization that more work does not mean proportionally more productivity. Quite the opposite.

Lazy programmer predictive modeling will foresee purpose and economy, eventually finding the least amount of work necessary for producing the most necessary results.

Our strengths and weaknesses are all different. I tend to “see the solution“ in the first fifteen minutes thinking about a problem, even when the technical implementation takes weeks or months of implementation drudgery.

Don’t burn yourself out. Let more work happen as background processing, practice conservation of intellectual time. Do not over caffeinate. Take exercise breaks (yes you nerds.) Eat properly.

TBH, going through ten years of grind may well be intrinsically necessary in cultivating strategic foresight.

The only thing wrong with you are your expectations.

IME it's fairly variable day-to-day; four is probably about the median but two or fewer is not uncommon, I use those days to get caught up on easier tasks. What you're describing is completely normal and shouldn't cause distress.

> How can I take the number of hours I can work on hard coding problems towards the number of hours I can be awake?

Honestly I would say this shouldn't be a goal, even directionally. Do your best to optimise your space and time for focused work, and if it ends up that you're regularly able to sustain a whole day of focused work that's good, but even if you can't that's still the best you can do.

To that end, you'll really have to experiment with what works best for you. Sounds like you're getting good results in your work periods so start with what you're doing outside of them: diet, sleep, recreation, etc all have a sizeable impact on your ability to do good work.

It depends, big surprise. Do you find that you’re aligned with what you’re doing? See the big picture, long term, the big why? Deep thought is expensive, and time is scarce, psychological alignment is necessary to break through the barrier so to speak. I know because I procrastinate difficult problems and think more about the why to even get started. Then once you’ve gotten started, in the right zone, you milk it to the extreme, not changing context or even getting up from the chair for the day. Do you work out of curiosity, beauty, or some sort of ambition or the next paycheck? Look cool? I’m only grilling myself here because lowly motivations are frequent for me personally and being honest can lead you to ask the right question to just get back on the track / right train of thought.

Personal minute example, I want to look competent while presenting the solution -> what does the good solution look like? Hook your feelings into helping you solve the problem. Larger example: I want to become a researcher -> Reading the next page is the best thing I can do right now toward that. So with a why you can keep going and activate your mind to stay on track despite low energy.

What’s going on in your mind when you’re spent? Where do your thoughts go? This is for you to answer personally because it’s not anyones business. But usually you can redirect that energy even though it’s a lack of energy so to speak.

Maybe if you’re spent on hard coding, think about eventual applications, or software architecture. Think of the organization and the problems that can be solved with software. About the history, future, of coding. There are a lot of tangential thoughts that are still helpful to explore once you lack steam on the main path so to speak, and the exploratory low energy mode can lead you back to high energy or supplement the next high energy session with creative angles that would not be come across in a more alert state, like those fever dreams that are so vivid that your alert mind would never come up with them.

I break work up into types:

Type 3: Light conversations with colleagues, exchanging ideas in a light-hearted manner. Can engage in this kind of work 8+ hours a day

Type 2: Programming a greenfield project, working in a familiar codebase, solving easy problems. Participating in low-effort meetings. 6-8 hours a day max.

Type 1: Challenging problems, non-obvious solutions, messy codebases. Engaging in difficult conversations, leading meetings. 4-6 hours a day max.

I've found that when I'm well-rested and in a positive mental state, these are my capacities each day. I can temporarily go over, but much like sleep, I need to catch up (by working less). If I exceed any limits, my productivity is reduced until I get some rest (e.g. by taking an easy day or engaging in lower-level work the next day).

Plus I have hobbies and friends and family that I want to spend time with. Life isn't about maximizing work productivity.

I've seen four hours mentioned fairly often, as long as you are taking real breaks. It's possible to occasionally go longer, but only if broken up into smaller consecutive blocks. I'd say six hours in three two-hour blocks with an hour for lunch in one of the breaks. Be deliberate about disconnecting and walking away from work when done, exercise daily. Get enough sleep.

https://maxfrenzel.medium.com/in-praise-of-deep-work-full-di...

Knowledge work like this is not unlike a muscle. If you exercise it to the limit, you'll fatigue and need to take a rest for 1 or more days. If you keep doing it you'll become stronger over time. But don't neglect your need to rest, it's not abnormal to need a rest after doing a lot of knowledge work. I tap out after a couple hours of meetings and doing research/coding/testing/implementing too. More meetings == more fatigue, it's draining.

I never used pomodoro technique when I was more in control of my time (as a student), and could do 12-14h of focused work: interrupts would have killed off any flow.

However, that only really worked for solo work, and collaboration really spends my energy much faster.

The first question is why did you start doing pomodoro in the first place? What problem is it solving for you? Is there a different solution that does not cause wasteful interrupts?

Argh, another productivity post by some addicted person who tries to compensate its lack of self-worth and satisfaction - with more work. Who cares about being more productive? Not me, I'm doing enough for a paycheck.

With the "reliably" requirement, my number is "1".