Just finished this book - loved it!
I’ve been reading it concurrently with Programming Elixir 
I read 50% of Programming Elixir first (the language bits) and then jumped to Elixir in Action because it covers much of the same ground on the language side of things. This suited me perfectly because it saved me having to write notes (I find going over things is a great way to ‘repeat and reinforce’ what I’ve learnt). These two books are a fantastic combo if this is your preferred learning style too.
I am surprised this is Saša’s first book - it’s very well written. It moves at a quicker pace than Programming Elixir on the language side of things (which is another reason why I think they work very well together if read concurrently as mentioned above).
Saša also covers much more than just the fundamentals of the language; after the basics you cover processes and OTP in quite some detail (and from what I’ve read so far, goes into more detail here than PE). You actually build your own server process before he introduces you to GenServers (which I felt was an excellent way to demystify them) - you’ll definitely leave feeling as though you have a fantastic insight into Elixir and Erlang!
If you will be reading this together with Programming Elixir I recommend reading 50% of Programming Elixir first, then 100% of Elixir in Action, then finishing with the remainder of Programming Elixir (partly because of what I’ve said above and partly because PE’s been updated more recently - so when you’re done you will be relatively ‘up-to-date’ 
).
Overall, this book definitely gets a huge 
from me! If you haven’t got it - get it! Well done @sasajuric - I can’t wait to see what you put out next!
