This is the third book cover I have been discussing with Sebastian and he keeps surprising me with his understanding of the message you want to tell with your book and how the cover should lead into this. Awesome working with him!
Mark had a great idea: compile his work and blog posts on the Command Query Responsibility Segregation into an ebook. A great package to understand and dive into this pattern. You can find articles covering this subject on the web, but none of them go to the extend of this book. You should get it.
Mark originally launched his book with a cover featuring a photo of diagram that was done during one of his whiteboard sessions.
I thought we could add some mystery to this cover by recreating Mark's diagram but removing the details. No names, only abstract boxes. And this is what the book is about: understanding the pieces and collaborations that make this pattern interesting. They are for you to discover. Enjoy!