You can run your own local mirror for deb packages. In a pinch, you can grab the deb files from a machine that already has them installed and copy them to the new machine.
When doing projects in AWS China, we end up caching lots of stuff, e.g. ruby gems. It can be super slow and unreliable to get through the Great Firewall.
You can also use ASDF to manage Elixir, Erlang and Node. That makes it easier to manage multiple versions.
