I am halfway through the book, but there is no doubt this is definitely an excellent text. Topics are explained very clearly, with plenty of real examples coupled with nicely done diagrams. I particularly enjoy those diagrams. Not only because they are colorful, but also because the author shows the flow and briefly describes what is happening.
I am honestly taking a lot of notes and writing down ideas. The best thing you can do here is really to take a screenshot of those diagrams and keep them safe next to your notes as they make it even more clear.
The text covers up to date topics, not technologies that are now obsolete. There are plenty of appendix chapters, each describing in depth those technologies or protocols, which is either a nice recap or a good introduction to it to get the most our of the book.
Definitely a must read for anyone working in DevSecOps, APIs and/or microservices.