Why and how we wrote this book The velocity at which OpenStack environments are moving from proof-of-concepts to production deployments is leading to increasing questions and issues related to architecture design considerations. By and large these considerations are not addressed in the existing documentation, which typically focuses on the specifics of deployment and configuration options or operational considerations, rather than the bigger picture. We wrote this book to guide readers in designing an OpenStack architecture that meets the needs of their organization. This guide concentrates on identifying important design considerations for common cloud use cases and provides examples based on these design guidelines. This guide does not aim to provide explicit instructions for installing and configuring the cloud, but rather focuses on design principles as they relate to user requirements as well as technical and operational considerations. For specific guidance with installation and configuration there are a number of resources already available in the OpenStack documentation that help in that area. This book was written in a book sprint format, which is a facilitated, rapid development production method for books. For more information, see the Book Sprints website (www.booksprints.net). This book was written in five days during July 2014 while exhausting the M&M, Mountain Dew and healthy options supply, complete with juggling entertainment during lunches at VMware's headquarters in Palo Alto. The event was also documented on Twitter using the #OpenStackDesign hashtag. The Book Sprint was facilitated by Faith Bosworth and Adam Hyde. We would like to thank VMware for their generous hospitality, as well as our employers, Cisco, Cloudscaling, Comcast, EMC, Mirantis, Rackspace, Red Hat, Verizon, and VMware, for enabling us to contribute our time. We would especially like to thank Anne Gentle and Kenneth Hui for all of their shepherding and organization in making this happen. The author team includes: Kenneth Hui (EMC) @hui_kenneth Alexandra Settle (Rackspace) @dewsday Anthony Veiga (Comcast) @daaelar Beth Cohen (Verizon) @bfcohen Kevin Jackson (Rackspace) @itarchitectkev Maish Saidel-Keesing (Cisco) @maishsk Nick Chase (Mirantis) @NickChase Scott Lowe (VMware) @scott_lowe Sean Collins (Comcast) @sc68cal Sean Winn (Cloudscaling) @seanmwinn Sebastian Gutierrez (Red Hat) @gutseb Stephen Gordon (Red Hat) @xsgordon Vinny Valdez (Red Hat) @VinnyValdez