I heavily utilize virtual desktops in my workflow. Always 10 on each monitor, accessed by Ctrl-{0..9}. Switching between monitors by AltGr+{1..n}. Programs always stay on the same virtual desktop no, so terminals on 2, browsers on 3 and so on. This enables me to access more or less any window in under a second, never having to look for it visually.

I usually work with 4 or 5 24" monitors, as a single program seldom needs more space for me. What he ultrawide brings to the table is the capability under Linux to create arbitrary virtual monitors.

I can for example have two evenly created monitors (two 27"). My usual for development is three, split as 2:3:2.

Another possibility is using a small script that analyses movie resolution and creates two monitors, one with the exact aspect ratio of the movie, eliminating black borders, and another for using while watching said movie :)

As Linux sees them as separate monitors, I can also have easily managed screen sharing.

Having the flexibility of software defining my monitors has been great as a developer; separation of many, screenwise often small, applications is highly useful to me. A couple of quick scripts to switch between different setups has integrated it nicely into the workflow, and I usually changes monitor config at least a couple of times per day.