Today we talk with Ethan Jackson about Cloud applications.  Cloud applications are web-based distributed systems deployed over a fluctuating set of computing nodes and services. The design of cloud applications is particularly challenging because few assumptions can be made about the connectivity of nodes, the availability of services, and the long-term evolution of the computing fabric. Ethan describes a new approach to architecting cloud applications. His approach gives developers a powerful set of abstractions that they can use to engineer systems beyond a client-server architecture, while understanding the behavior of their applications in a cloud environment. This is part 1, where we introduce the basic concepts on the whiteboard. BAM project home page  The Research in Software Engineering team (RiSE) coordinates Microsoft's research in Software Engineering in Redmond, USA.