In the previous chapters, we looked at basic integration patterns. In Chapter 2, Integrating Our First Two Applications, we created a point-to-point integration, integrating a SOAP inbound service and a REST outbound service, and in Chapter 3, Distribute Messages Using the Pub-Sub Model, we converted a simple integration into a publish and subscribe pair of integrations and extended it with multiple subscribers.

So far we have demonstrated the use of our own service definitions for the trigger services and online tooling to document and mock our back-end services. In this chapter we're going to demonstrate the integration between existing SaaS (Software as a Service) applications. Integrating with SaaS applications is getting more and more important now that companies are moving away from on-premises application to Cloud hosted solutions. Where we have the need to share data between on-premises applications, for example integrating our CRM...