He explains that concurrent programming is hard just like memory management because you need to balance correctness and performance.
So as long as you stick to the simplest rules of concurrent programming - stateless services and immutable objects, it will be a breeze to wire your services to any producer or consumer.
The actor model facilitates concurrent programming by allowing a safer mechanism for message-passing between processes (or actors).
This article describes some potential problems due to non-reentrancy of the function in parallel and concurrent programming.
Not every developer needs to know about concurrency in such detail, and not every engineer is up to the level of this book, but there's no better survey of concurrent programming than this.
You can still do more stuff, but you have to do it using concurrent programming.
