Not to just toss around anecdotes, but I once rewrote an email service in elixir for a company from a literal sketch on a piece of printer paper describing what their old system did. The new service ran on 1 server vs half a dozen and was both faster at crunching through their mail queue and used far fewer resources. Some tasks are embarrassingly parallelization and the BEAM excels at those tasks. Sure you might want features it doesn't have for certain systems, but for some things it really is the right tool.
Whatsapp took over the world running on Erlang/BEAM, with barely any servers and a few engineers. I honestly don't know what could be a better success story than that, but Discord has also done pretty well. The BEAM + Rust combination is looking scarily effective right now.
I'd be willing to accept the argument that Whatsapp happened to have assembled an uncommonly good team, but it is a signal.
Yeah the BEAM with some Rust NIFs is a great combo. I'd definitely consider it in the future for many types of problems and anything involving a HTTP or GraphQL interface.
