Cloud Computing is one of the most notorious hypes in today’s Web information systems research and practice. In this talk, I introduce the basic notions and challenges associated with Cloud Computing, and position my own research agenda within the larger cloud computing, services and software engineering communities. Furthermore, I provide an in-depth look under the hood of CloudScale. CloudScale is an experimental middleware for deploying applications in the Infrastructure-as-a-Service cloud, which we have devised at Vienna University of Technology. I explain how to build applications based on CloudScale, and how such systems can scale up and down via automated resource provisioning. I detail the practical advantages that the CloudScale model offers over competing paradigms. Finally, I conclude the talk with an outlook on current research issues in Cloud Computing, both, within and outside of the CloudScale system.