Which hardware to ship to customer as SSH “jumpbox”?

I'm looking for a small / cheap hardware appliance that can be shipped to locations and just need to be plugged into a network cable / power. It should then connect to some kind of cloud and be accessible for me so I can deploy code to it or just SSH into it. It's important that there's no maintenance necessary and it just auto-connects in case there's issues.

I found products which look somewhat related:

- https://kubesail.com/blog/pibox-raspberry-pi-powered-nas

- https://docs.balena.io/learn/getting-started/raspberrypi3/python/

- https://en.wikipedia.org/wiki/RIPE_Atlas

Any hints on keywords on how to find something like that? My main use case would be to run a Squid proxy at the location.

Thanks!