Elm on the frontend, Elixir on the backend. Elm because then you can mostly ignore JS et. al. You can hire a normal person (anyone who can solve Sudoku puzzle

Elm on the frontend, Elixir on the backend. Elm because then you can mostly ignore JS et. al. You can hire a normal person (anyone who can solve Sudoku puzzles) and train them up to make working web UI in a week or two. Elm makes that possible. It's like what if you could start a professional bakery with just an Easy-Bake Oven. Elixir because it's more approachable than Erlang. Erlang (the BEAM & OTP) because it's much closer to the domain (if you're making a complex interactive multi-user kind of a thing, eh? If not then it doesn't really matter what backend stack you use.)