Over the course of this chapter, we took a look at why EAI is necessary for the proper functioning of enterprise business processes. Once we understood the necessity of EAI, we then moved on to understand the approach toward EAI, where we explored the point-to-point integration of application, and why the process of point-to-point integration is problematic. We then explored the traditional way of implementing EAI through the use of a broker middleware model, before continuing the discussion about how the model transformed as SOA came into place, and how the ESB took the place of the broker-based model.

We then moved on to understanding the different patterns that are in EAI and learned about the mediation and federation integration patterns of connecting the different applications, followed by understanding how the different access patterns, such as asynchronous and synchronous access, work in the transportation of information from one application to another. We concluded this chapter by exploring some of the issues that plague the successful integration of applications in an enterprise.

As we move to the next chapter, we'll learn about how the introduction of microservices has changed the EAI landscape and has ousted the use of the ESB, and how it's now being replaced by distributed message brokers and API gateways.