Applied Akka Patterns is in my opinion the de facto Akka book regarding Distributed Domain-Driven Design(ed) Systems.
Some things to get clear before getting to the actual review - this is not a book that focuses on writing code. It has the minimum amount of code snippets that are never shown to function in one app. Needlessly to say, as in **most** "Patterns" books, you can't copy-paste code snippets without providing the glue code by yourself. The focus is more on the theory, bigger picture and applicability of Akka in the design of a distributed system, which in my opinion is the right approach.
So, the actual review.
The start tackles the actor model head first in 1-2 chapters and how it's applied in Akka.
Showing different "short-comings" when mixing the Actor model with other paradigms such as FP-like Futures.
After you have the basics down, the book moves into software design issues such as achieving a good separation of actor responsibility while tackling issues with State, Complexity and "Eventual consistency" (although it's not explicitly mentioned in that part of the book). It's very important to take to heart the narrative's focus on avoiding complexity and "ask" pattern which results into highly-coupled actors. There's a second goal that's being put which is applying Domain-Driven-Design as a solution.
And at this point the book goes deep into designing distributed systems that benefit from Akka.
There are numerous patterns mentioned briefly, but I am especially fond of the focus spent on explaining how to design the consumers right. A big focus of designing distributed systems falls into the "wrong" (or let's say harder to change) places, instead of consumers. So, the book does a good service to explain basic patterns of securing a good data flow with scalability, throughput and availability in mind. Of course it's not a bag of chips, so you can't have them all at once. If you are familiar with message queue systems or distributed transactional log such as Kafka, you'll be refreshing knowledge you already have. But it's a good point for others to make a solid foundation.
As you may already know at this point, I highly recommend this book. It's very detailed in how to design distributed systems.