F2F rounds were ok and the interviewer seemed professional. Async take-home assignment is a total waste of time and no point in taking it if it requires you to learn Elixir/Phoenix as they evaluate your code as if you're super proficient in it. I invested quite a good amount of time in learning the language and framework but the review was quite strict and needed you to be proficient. So it's a total waste of time. Stop entertaining such a hiring process, they clearly don't have any respect for the time you invested in them.