Elixir. While Rust and Go get way more exposure lately, they're mostly designed for systems programming. Many more of us do web development, and it's really amazing how fast Elixir has become a very cool and
mature environment for developing great web apps.
Elixir is a really cool language, and also a great way to learn functional programming. But more than that, it gets all the non-languagy stuff right. The build system is amazing, your code hot-reloads out of the box, dependency management is very well done (source-only, git-friendly, project-local, etc), the community is very friendly and going fast.
And code scales by default. I might exaggerate here, but sometimes it feels like need to really try to write code that's hard to spread across servers. If you consider it's non-trivial to even use all your CPU cores on Node.js, the Erlang VM will blow your mind.
Elixir is a really cool language, and also a great way to learn functional programming. But more than that, it gets all the non-languagy stuff right. The build system is amazing, your code hot-reloads out of the box, dependency management is very well done (source-only, git-friendly, project-local, etc), the community is very friendly and going fast.
And code scales by default. I might exaggerate here, but sometimes it feels like need to really try to write code that's hard to spread across servers. If you consider it's non-trivial to even use all your CPU cores on Node.js, the Erlang VM will blow your mind.