What is the productivity advantage of Elixir/Phoenix over other frameworks when using it for implementing more mundane SaaS (some dashboards, some CRUD,...) rather than the game lobby feature mentioned in the post?
I am a developer with significant non-web development experience (Although I know pure JS and Erlang quite well), who is interested in learning some full-stack development to implement a SaaS on the side and would like to zone in on the most productive framework possible.
For me it's not just the framework (although that is nice) but really the VM that it runs under (BEAM/OTP). Running an app on the BEAM means removing the need for external servers like redis/memcache for cacheing and whatever queue management system you pick.
For a SaaS app this means instead of trying to orchestrate a bunch of services via some complex system (k8s, etc) you run everything under one VM that both scales across both local CPU cores and distributed nodes in the same network easily.
As for dashboards and CRUD UI that is improving in the latest Phoenix release. I have a 5 year old Phoenix app that I wrote that is still running in production and I generated all of the backend admin and most of the frontend using Phoenix's generators. However that did result in a lot of nearly duplicate view code. With 1.7's focus on shared common UI components the shear volume of template code is reduced, (but not eliminated).
If I were you I'd wait for 1.7 to fully release and then try it out for a couple of hours and generate some simple app to get a feel for it. I've been programming professionally for 30+ years and I've written in a lot of languages and writing Elixir code just feels good. José Valim got a lot right with Elixir (and he sets a great tone - just read his comments in this very comment section).
Although, if I were an absolute beginner, I might still consider waiting a little bit for the various resources to be updated to 1.7. That seems to be happening fast, at least. Or just go for the excellent Phoenix guides, which are already updated: https://hexdocs.pm/phoenix/overview.html
As long as you don't have any dynamic part to your app, it's pretty much the same, it's the dynamic areas that are very very productive with live view.
I've implemented a simple multiplayer card game in about a day for example.
I am a developer with significant non-web development experience (Although I know pure JS and Erlang quite well), who is interested in learning some full-stack development to implement a SaaS on the side and would like to zone in on the most productive framework possible.