I worked on a project a few years ago that was a mixture of Erlang and Ruby. Most of us were new to Erlang, coming from a Ruby background. We wanted to use Erlang to its strengths for high availability and to make the platform distributed, and Ruby (via BERT/Ernie) to its strengths for business logic.
Unfortunately Ernie didn't work as well as it advertised, had many edge cases, and in the end it was a big bottleneck (it would have been faster to ditch Erlang and use plain Ruby).
In the end we wrote everything in Erlang. It wasn't that hard in the end, and the reason why we went down the Ruby route in the first place was because the platform was over-engineered to be as generic as possible (which wasn't needed), so we didn't actually lose anything.
Do you have any experience with Elixir? I'm hearing that Ruby devs like it for similar syntax that runs on the Erlang runtime....(But I don't really know much about it, but I am curious.)
I learnt Erlang before Elixir became popular. Other than a few sanity changes (like ordering of arguments for some built in functions), I prefer the Erlang syntax. The syntax is Ruby like, but it's still different enough.
Unfortunately Ernie didn't work as well as it advertised, had many edge cases, and in the end it was a big bottleneck (it would have been faster to ditch Erlang and use plain Ruby).
In the end we wrote everything in Erlang. It wasn't that hard in the end, and the reason why we went down the Ruby route in the first place was because the platform was over-engineered to be as generic as possible (which wasn't needed), so we didn't actually lose anything.