The choice may have been different if we were to start the project now. But I believe that interfaces are what matters. Also, we kind of didn't have a choice on the frontend. If you would like to see, our migration layer and database schema design is written in Elixir and Ecto. As for JS, there are definitely shortcomings but performance-wise, Node is good enough on the server side for the time being.

Do you have any specific questions?