Ask HN: What should a back end software eng learn to build simple UIs for apps?

I was in the same boat for quite a long while. My search thus far has yielded Vue as the simplest single page app framework to consume an api using no central state and optionally an eventbus.

For server side rendered pages like rails, prefer crystal+kemal or possibly elixir+phoenix.

What styles of languages do you prefer?

I am a backend engineer and I really like working with React.