The iPad Pro deserves all the good reviews. I use it all the time, professionally and privately, and like it more than I ever expected to. I recently decided to take things one step further and try using it for web development as well.
Now, it's not all about the iPad — the magic actually happens in the cloud. I use a $5/month Ubuntu server hosted by Digital Ocean. I could probably get away with less using AWS, but I like Digital Ocean's shiny interface. I'm only human.
Blink for iOS is a great shell that allows me to SSH into my development server. The IP address is available in Digital Ocean's control panel. Swedish 4G is quite good so there is no noticeable lag.
I host my projects on GitHub. To access them, I generated a new SSH key and hooked it up to my GitHub account. After that, I can clone/push/pull projects freely. When running my build scripts, I ran into a bunch of issues with packages, compilers and dependencies. After 30 minutes of Stack Overflow and apt-geting things all my build scripts were working smoothly. Development time!
My current project involves Jekyll which serves a static web site to a local url like localhost:4000. To make the site accessible from Safari I use Localtunnel which takes any local URL and gives it a random, publicly accessible URL.
Vim is my editor of choice on the Mac, so that's how I edit files on the iPad as well. It's a pain to learn, but it's worth it — being able to feel right at home on any unix machine is pretty neat. To make sure that my build script's output doesn't interrupt Vim I send the build script's output to/dev/null.
The iOS 11 beta has even better split screen support than previous generations of iOS. Windows can be arranged in custom 25%-50%-75% arrangements with another window floating on top.
All of this makes developing on the iPad Pro pretty great. I won't use it as my main development machine but I might settle for the iPad next time I leave town for a few days.