Microsoft provides a very comprehensive and powerful set of “middleware” services that cover identity, transactions, long-running processes, messaging, and very rich integration capabilities. Other vendors often bundle these capabilities in form on an “Enterprise Service Bus” offering that is sold in form of an installable server software or even an appliance. Where is Microsoft’s elusive Enterprise Service Bus? Well, we’re believing in federation more than in centralization and have learned a great number of lessons while building some of the largest distributed systems in the world, including Windows Azure itself, that have enough challenges that traditionally fall within the scope of ESBs but for which the many of the touted ESB benefits would have been more than counterproductive. In this session, Clemens Vasters form the Windows Azure Service Bus team presents the key challenges with the ESB model and how Windows Azure scales to its workloads and also to the many people who build it by using a federated services model that turns the ESB notion on its head. Technologies: Windows Azure Service Bus, BizTalk Server and Services, Windows Azure Active Directory and Access Control, Workflow, Transactions