Have you checked out Elixir? - Can be deployed to Heroku or Fly.io without much effort - Well designed tools like mix - There is a thriving community - "bas

Have you checked out Elixir? - Can be deployed to Heroku or Fly.io without much effort - Well designed tools like mix - There is a thriving community - "basic open source libraries" highly depends on the context, but yes there are not as many as for more popular languages (yet)