* Contributing to a project/mission that feels worthwhile.
* Practicing good craft/professionalism. (Which doesn't necessarily mean always being able to do the best code/architecture/process, but to work well within your constraints.)
* Being part of a good team.
Though ideally you have all three, and perhaps other things, as well.
I agree about abstract, and maybe that ties into feelings about contributing. For a while, I was working with only code related to aviation, and I felt good about my modest role in some good processes, but I don't actually like flying, so I hadn't been up-close with airplanes in a while. One day, it occurred to me that it would be a boost of inspiration to go see some of the real-world aircraft and activity. Aviation is really amazing concert of processes and technology, most of it not visible, but there's something to be said for tangible. Since I wasn't aware of anything like an observation window in my airport that (post-9/11) one could access without a ticket, I spent some time finding and printing photos of some of the aircraft I'd been working with, and decorated my office, which did give a boost.
On the one hand we're killing the earth, polluting and creating a nightmare existence for our children. On the other hand, buy more stuff! I don't understand how anyone can justify this to themselves and I believe the resultant self doubt is a key factor in burnout.
P.s. never mention this at work... It's the elephant in every meeting room.
I think doing things in the real world that you believe to be useful can provide meaning (e.g., baker making bread that that you see people enjoy, or a doctor checking a kid and being thanked by parents). However, to me, it is orthogonal to working with physical objects. I am perfectly happy working with text on screen that produces plots and formulas as long as I convince myself that those could be useful for something I consider important.
The big problem I believe is the fact that many people know that what their work will be used for is useless to a society (or even mildly harmful). I suspect that people working on targeting ads to sell unneeded junk, hooking kids on time-wasting apps or winning in a zero-sum game of HFT know deep inside that their work is a waste at best.
This can be rationalized away for a while, but not being able to answer "what am I doing this for?" can eat one up long term. My 2c.