I'm actually new to the Erlang/Elixir ecosystem. This is my first project using it. I wanted a full-stack framework that allowed me to move really fast but I also wanted to have a nice user experience (similar to single-page applications) and good performance to avoid spending too much on servers.
I found Phoenix [1] and I loved it! I've been very productive using it. I'm finding LiveView to have a very good UX, almost as good as a single-page application.
And I'm quite impressed with the performance. For this demo, I'm using the cheapest machine on fly.io. Peak usage was 184MB RAM and 8% CPU (most of the time it's under 3%).