Consider the Lenovo Nano: https://www.lenovo.com/us/en/c/desktops/thinkcentre/m-nano-s...

I have a couple of the ThinkCentre Nano computers. They are tiny, a fat fit for a pocket, but easily transported if you wanted to. AMD Ryzen processor and plenty of ram with SSD.

Still need power though... and I am not crazy about the power connector though (seems too proprietary) but it seems very sturdy at least.