Yea solving hard problems can be quite enjoyable, but can easily become a burden on your mind/body over time. When you're clearly making progress, then everything feels wonderful even if it's challenging. But when you're stuck, when your code/model isn't working as designed, if there is a clear gap between your current state of understanding and the amount required to solve the problem effectively, then you can fall quickly into despair. It's made worse when you see others doing similar work to what you do, but being far more successful at it. And made even worse, when you tie parts of your identity to the problem you're trying to solve, and the code you write. But that's the nature of what you're trying to do, so it isn't all bad.

3. "Best Practices" having changed every time I go back to the frontend

Nah, I have another one: Being confronted with my own stupidity and my own limits in mental capacity. The shocking thing is that this never goes away, even after decades of practice.

Never?

Never some intractable bug, that didn't seem to have any relation to the source code you're reading?

I mostly find programming fun, I’ve been doing it most of my life, but I will admit that engineering can be pretty agonizing. I enjoy the stuff, I enjoy the algorithmic stuff, and I enjoy implementing the math and algorithms, but that’s only about half of any programming job I have had.

I derive zero enjoyment from Kubernetes configs, or Terraform, or fucking around with log settings, or screwing around with all the knobs for Kafka. That stuff is agonizing.

Yeah same. I've been doing this for fun since I was like 9 years old. 30 years later it's still fun.

You must not talk to other developers ;)

But seriously, sometimes its not the code, it's the human factor that's painful, other times, well it's JavaScript.