The article explains how to set up a Service-Oriented Architecture (SOA) using an Enterprise Service Bus (ESB) and the Ada Web Server (AWS). It defines key SOA terms like service, service provider, and service consumer, and discusses principles like loose coupling and statelessness. The ESB is described, along with the Mule ESB and its benefits. The Ada Web Server is introduced, detailing its capabilities and how to integrate it into an Ada application. The article shows how to create a callback function in AWS and connect it to an ESB endpoint, making it a crucial part of building a reliable SOA system.