Who Should Read This book?
This book is written for those who create or operate complex technology. That's primarily software engineers and systems administrators, but it also includes a variety of related roles, including analysts or architects. There's also a lot of information in here for security professionals, so this book should be useful to them and those who work with them. Different parts of the book are designed for different people—in general, the early chapters are for generalists (or specialists in something other than security), while the end of the book speaks more to security specialists.
You don't need to be a security expert, professional, or even enthusiast to get substantial benefit from this book. I assume that you understand that there are people out there whose interests and desires don't line up with yours. For example, maybe they'd like to take money from you, or they may have other goals, like puffing themselves up at your expense...