DX == developer experience? If not, I will delete this For me, the answer is Elixir: - takes the good parts of Ruby and applies them in a functional paradigm

DX == developer experience? If not, I will delete this For me, the answer is Elixir: - takes the good parts of Ruby and applies them in a functional paradigm (data is separated from behaviour as opposed to encapsulated in complex class hierarchies), - standarized documentation, strong emphasis on tests, it even has documentation that can double as a test (see doctests), - quite recent language but already matured because it builds upon Erlang (which you will need rarely to be productive, if at all), - a lot of exciting things going on in the ecosystem, see Phoenix Liveview. Probably has the most friendly community that I've encountered too. The language author Jose Valim is all over the Internet answering everyone's questions and looks like this behaviour is poisonous.