While there are many similarities between SQL Server and SQL Azure, there are different kinds of applications that are easier to build in one or the other. One of the major differences relates to how to build an application that “scales”. This presentation will provide an introduction into the difference between scale-up (SQL Server) and scale-out (SQL Azure) architectures and give you a primer on how you can build a large, Internet-facing service that can scale to arbitrarily large sizes on commodity hardware. This talk is targeted at SQL Server practitioners to give them a working knowledge of how the two platforms differ based on Microsoft’s experiences with its largest Software-as-a-Service (SaaS) customers running on SQL Azure.