While we didn't call it DevOps back in 2012, when I joined Gap Inc.,we working towards achieving some of its goals then. Over the ensuing years we got reasonably good at it. I read Gene Kim's book, The Phoenix Project, a couple years back and so was excited to learn he was working on a new book entitled The DevOps Handbook.
I pre-ordered the book on Amazon and wrote a four part summary as I read it. This is as must read book if your in IT today. The book is long so if you are in a hurry and want to read my take on the most important concepts the summary is for you. It also serves as a good review if you've read it and just want to keep it in your head.