You can probably do it for a while. But, there is some sort of long term mental reserve that is depleted as we work. You would deplete these reserves more rapidly and need to take a major vacation much sooner than if you had one job. The quality of your work would suffer at the second job as there are also reserves that are depleted daily and restored during sleep.<p>In one sense you would be abusing the tools of your profession. There is a common admonition that "A craftsman does not abuse his tools".<p>You must make your own decision, but I would never do it.
So, I've never taken two full time jobs in a traditional sense. But, when I was starting my consultancy I took on two full time projects. The ONLY reason this worked was that I was able to control meeting days, hours and set expectations accordingly. So as a consultant, yes I was working two 35hr weeks (sometimes more) but I had control over the work schedule (mostly) and had the ability to say no to certain demands without harm. And there was never an expectation I was "only" working on company Y since they knew I was running an agency. I distinctly never called myself a freelancer even when it was just me starting it out, because then they just treat you like an employee they don't have to give benefits too.<p>So that all said, could you pull it off for a year? Yea, you probably could, but the personal toll it will take on you will be high and the chances of you upsetting one or both is pretty high since you won't control your schedule or meeting times etc. And what happens when the remote employer has an emergent issue and you are at your other full time position, you cannot ethically use employer #1's equipment, network or bandwidth to benefit employer #2. In fact it is generally a terminating offense if you did so without their knowledge and blessing.<p>My recommendation is don't do it as an FTE. And even as a consultant it took a major tool on me the first couple years I had to do that while I was hiring people. But I had to build up the reserves to hire people, so it was the cost of wanting to be in business for myself.
In my experience, no.<p>A full-time software engineer job is usually 9+ hours per day. Add even a minimal commute, and you're getting maybe 4 hours sleep. That'll only work for a few weeks at most.<p>If you found jobs that were a genuine 7h or 8h a day, 5 days a week, with no need to ever do "over time" or whatever ... that's minimum 14h/day, an hour for commuting, an hour for eating and showering, and do all your life stuff on the weekend, and you've got 8 hours to sleep.<p>So I guess it could theoretically work, but why would you do that to yourself?