Maybe things have changed but I used Erlang/OTP for a while, and at the time, it wasn't easy to learn it by yourself. The language itself was not an issue, but

Maybe things have changed but I used Erlang/OTP for a while, and at the time, it wasn't easy to learn it by yourself. The language itself was not an issue, but building a useful program required good familiarity with the library ecosystem, i.e. the user-written modules that were scattered all over Github and not just the standard libraries that came with the system. There were several books on Erlang that each consciously decided to document only the standard stuff. So the only way to know what was where was maintain contact with other Erlang developers, go to the (excellent) Erlang Factory conferences (now called Code BEAM), and so on. Inside a company I think you need a critical mass of devs to keep a project going and also keep track of the outside Erlang world, which was in a state of flux and probably still is. In Python or C++ or even Haskell, it's easier to get by with some web searches and online chats. That all said, Erlang/Elixir/BEAM is a great way to write concurrent systems, much better than the async madness that was inflicted on us by Node and has more recently spread into Python. The book learnyousomeerlang.com is a good place to start. Elixir is newer and has different (Ruby-like instead of Prolog-like) syntax, but is mostly the same underneath, from what I've been told.