I have read Testing Elixir and am reading both A Common Sense Guide to Data Structure and Algorithms and Concurrent Data Processing in Elixir (Both have remarkably similar and beautiful cover designs).
All three are really good, especially the Concurrent Data Processing in Elixir. I will be referencing the Algorithm book in Programming Crystal Book club and after that books ends, I intend to start one on Concurrent Data Processing with Elixir. It’s awesome that these books are on sale!