This book focusses on the visual communication and documentation of software architecture. I’ve seen a number of debates over the years about whether software development is an art, a craft or an engineering discipline. Although I think it should be an engineering discipline, I believe we’re a number of years away from this being a reality. So while this book doesn’t present a formalised, standardised method to communicate software architecture, it does provide a collection of lightweight ideas and techniques that thousands of people across the world find useful. The core of this is my “C4 software architecture model” and the “software guidebook”. You’ll also find discussion about notation, the various uses for diagrams, the value of creating a model and tooling.