The Web, as a ubiquitous distributed computing platform, has changed dramatically the way we build information systems, evolving from monolithic applications to an open model that enables real-time and federated information access, unifying the user experience across business processes. The industry has coined a new term for this latest evolution: connected systems. Unlike distributed systems, they are not just about distributing workload or ensuring fail-over, but rather about leveraging connectivity to enable specialized software agents to perform units of work cooperatively and opportunistically by exposing and consuming each other’s services to fulfill a common goal. To reach their fullest benefits, connected systems require a new application model that relies exclusively on the consumption and composition of autonomous services. This new blueprint is poised to reshape the information systems’ architecture, infrastructure, delivery technologies, programming languages, deployment, and management models. The goal of this chapter is to help you understand why and how IT should evolve the enterprise architecture toward a service-oriented composite application model.