As jmiller099 suggested, AIDE is a nice IDE that runs on an Android. I used to use it before I switched to an iPhone.

On my iPhone and iPad I use an SSH app to access a VPS that I use only for coding, running machine learning problems overnight, etc. This works well on an iPad but is cumbersome on an iPhone. I like emacs, and remote dev in an SSH session works for me.

On my iPhone and iPad I really enjoy Raskell: a very nice Haskell IDE that is fine for writing short programs.

For Python, Pythonista is a very good IDE! Really good.

I like traveling lite with only a phone. I would have real difficulties doing what you do, using a smartphone as only personal computer but what you do would really help work/life balance.

on android a developer can develop for android on android itself. applies to java, ndk, and even console c/cpp apps. product is called AIDE. root not required.

furthermore, can use rooted android to develop for windows and windows ce by using tcc in conjunction with the aforementioned ndk to build tcc on the phone.

I researched this while I was still homeless. I was told you could develop in Kivy on an Android device (at least on a tablet). I was never able to make it work, but I don't have serious programming experience. I just know a little CSS and HTML. Also, that was a few years ago. Perhaps things have improved.

https://kivy.org/

https://en.wikipedia.org/wiki/Kivy_(framework)

If you want a Linux shell there's Termux, you can use vim, compilers, python, etc.