But recently I read the Programming Phoenix 1.4 book (written by the authors of Elixir and Phoenix) and it really filled in a ton of gaps and made so many things click together. I can't speak highly enough about it. In fact, finishing that book today is what provoked me to write my comment here. The book might be exactly what you're looking for as like 5% of the book focuses on the super basics and a toy example, but 95% of the book focuses on building up a pretty real app and layering on features as you go. It's also up to date and feature complete even though the book is labeled as a beta release.
By the time you finish the book, you exercise a ton of interesting things along the way (including how to take advantage of Erlang's VM to build features that would be 100x more effort and probably 10x worse in other tech stacks). You definitely don't just build a simple todo app. I don't even want to say what we build in the end because it feels like a spoiler. I only say that because when I hit the last section of the book I had no idea what was coming and was blown away by what it covers. It literally made me smile for hours just thinking about how badass everything is when it all comes together.
