The referenced post is from 2020, and nubank still posts clojure content and sponsors the big clojure conference, so I’d be shocked if they were dropping clojure.
Their tech stack is probably enormous, it wouldn’t surprise me if they’re using both for different things
Also the referenced post is about them acquiring plataformatec, not about using elixir. Jose Valim (the creator of elixir) left plataformatec after the nubank acquisition in order to continue developing elixir, I've never heard of nubank using elixir, afaik they're solidly a clojure shop with no plans on changing.
it's just an internal I/O-bound project, where BEAM concurrency makes lots of sense. Grown from an engineer's side project as it was useful and working well, not a company-wide effort to bet on Elixir
A blog post by them about this: https://building.nubank.com/tech-perspectives-behind-nubanks...