I loved working with Sebastian on my covers for the Lean Startup for Developers books (http://ls4d.com). Sebastian really takes the time to understand what message you are trying to convey in your book and then he will create a few different designs. During the discussion of the different options he clearly explains the thoughts behind the design. The whole process was very pleasant and open. And of course I love the end result!
Mark was looking for a cover to complement the two books that he is currently writing. We agreed that the main goal for the cover would be to show that the lean startup movement is incomplete if you are missing the business side or the technical side of it.
Heavily influenced by the Ensō symbol, we wanted to take away his strength, elegance and enlightenment. But also add the chaos and disorder that a developer might see when approaching lean for the first time. Hence the confused arrows in the middle of the two covers. They seem going no where, but when stepping back, they actually go with with the flow of the Ensō circle.
Check out both books on Leanpub