How many displays are enough to be a good developer?

I had my first computer nearly 30 years ago. Since then I always desired to see more things on the screen at the same time. Because context-switching is a big problem for me. If I spend some time on something, I lost track on the previous one. Something should remember it to me. Most of the time, best approach was being able to see the other waiting tasks on my screen all the time. Because of that, multiple screen setups always seemed cool and great to me. Until a few years ago...

Ergonomics while working is an increasingly important topic for me (I know, I'm getting old). A few years ago I had frozen neck and it was painful. I visited physiotherapist and he told me same old story about how to properly sit in front of the computer display. As you probably already now, you should look at your display directly, without needing to turn your head. But, how this will be possible if you have 2 (or more) screens?

I tried to put my second monitor vertically, then above the main one, then at an angle, none of them worked. My eyes kept drifting, my neck kept twisting, and my focus scattered. What I realized was simple: I wasn’t using more screens to be productive; I was using them to avoid friction. The friction of closing something, reopening it, or deciding what actually mattered.

Excluding the jobs that really need persistent visibility—like traders, sysadmins, or live ops engineers—most of us code on one thing at a time. You’re either reading, writing, debugging, or testing. Context switching doesn’t get easier with more displays; it just gets disguised. Every open window whispers for attention.

1. You always use one monitor as your main. Everything else is secondary clutter, even if you pretend it’s “for reference.”
2. Extra screens are distracting. They encourage multitasking instead of deep work.
3. The real problem isn’t screen space, it’s mental space.

Then I returned back to single display setup. Just large enough to see a web page with developer tools and my code IDE side by side (I use 32" 4K display). Sometimes I use my iPad to check my notes while I'm making an online presentation by sharing my screen. That's it.

Since around 3 years, I've been working with this setup and I feel pretty comfortable now. Even though filling the whole desk (or even the whole wall) with displays still looks cool, I don't see any practical advantage to it.

So how many displays are enough to be a good developer? One. And even that one should have boundaries, full screen, no notifications, no Slack in the corner. Focus beats surface area every time.