Well I do like Elixir in the back end, with PostgreSQL.
For the architecture, I use Commanded at work. It was complicated to grasp at first but now it makes a lot more sense.
Not a great fan of document based databases.
For me Elixir’s solves all the problems I can encounter. Lately I’ve used GenStage to handle synchronisation on some events. I’m eager to see how it’d be handled in another language.