The official docs for Elixir or Phoenix framework go a long way. One thing that sticks out above the rest for me is Elixir koans[0]. They’re extremely rudimentary but I think the project showcases Elixir’s hot reloading if I’m not mistaken and it’s very fluid. Other follow along courses may have taken this approach but I was extremely impressed by how everything fits together.
[0] https://github.com/elixirkoans/elixir-koans