Not everything is good tbh, when you see the pain it is to deploy an Erlang app in 2020 ...
mix release
Compiles everything, tar/gz's it, sends it to a private s3 bucket. On your server side, you periodically watch the s3 bucket, and when one of your nodes detects a relup, it downloads from the s3 bucket, kills itself. Systemd then restarts it, kicking into the newest version.
That's it. This is maybe about 50-100 lines of code, one external library (pick your AWS library of choice), and one systemd script. I think there's even a library for managing systemd from within the BEAM now.
If you want to be more sophisticated (a rolling blue-green deploy across an erlang cluster) you could probably do it with transactional locks with the :global module in about an additional 100-ish lines of code, including fully verifying the soundness of newly upgraded nodes using telemetry.
I haven’t gotten around to actually trying it myself, but it advertises that it can compile Elixir projects into a single binary you can copy, paste & run (on Linux & MacOS). It’s not the greatest solution, and the mentioned ~0.5s startup time doesn’t make it great for cli tools when compared to Go/Rust/C.
I’m mostly just happy to see there are people out there trying to make Elixir/Erlang easier to use, as much as I love the language, some of the tooling and deployment methods (releases) make me groan.