This books targets people who have to work with Java and Java EE applications, especially people working on performance topics in local or distributed environments and production or development environments.
This book assumes that you are, at least, familiar with Java 8 development and some Java EE concepts. You don't need to be a Java EE guru, but a basic understanding of things such as Java proxying and interception will help you get up to speed with the concepts covered in the book.