I strongly feel that Erlang really, really needs more visibility in the world. It is an important language for distributed systems, but the language itself is startlingly spare, using recursion and pattern-matching in lieu of conditionals. There are two resources that I like, a 3 week Future Learn course [1] and Learn You Some Erlang [2].
It is my belief that the Erlang "process" is a true object, as opposed to Ruby/Java/C++ etc object which is, ultimately, a thin easily-torn veneer over global spaghetti.
WhatsApp's acquisition for $1B for a 57-person team that could run a large, world-wide messaging system with Erlang should also be considered a resounding endorsement.
Last but not least, I personally have come to see the overall trend toward statelessness is a coping mechanism to deal with bad technology.
(If I could change my name to ErlangJosh, and if it sounded good, I would.)
1. https://www.futurelearn.com/courses/functional-programming-e...