This article is quite good, especially part about bottleneck caused by single supervisor in ranch. However I have to say that title is a bit misleading because all of this has nothing to do with Elixir, it's all about Linux kernel and Erlang, cowboy and ranch are written in Erlang.
Having said that, I will add that I think it is good to have Elixir.
Having said that, I will add that I think it is good to have Elixir.