The Phoenix Web Framework, built in Elixir, is a web framework that hopes to stear away from JavaScript. Instead, it comes with a minimal JavaScript library that hooks into the frontend and only sends optimized diffs over stateful websockets. This results in very fast DOM updates and eliminates the need for complex frontend libraries and build pipelines within Elixir and Phoenix web applications.
Elixir is a functional programming language that is built with concurrency in mind. It has the ability to spin up lightweight processes with small memory footprints that can communicate with each other and have very low scheduling overhead. These stateful processes make for a perfect pairing with concurrent websocket communication. All of this alongside Phoenix ends up creating a very fast user experience and a very excellent developer experience.