Summary

In this chapter, you were shown around a monolith application and should now be familiar with the modules and the structure. You should also be able to run the application and use the UI to run experiments of your own. We also looked at how synchronous communication between components can work and the choices you might face when fetching data or sending commands. Then, in the last section, we implemented domain events in one of the modules. While this didn’t change much or add any new asynchronous communication methods, it does set a foundation for us to build on to make not just our modules more reactive but the entire application.

In the next chapter, we will learn about event sourcing and implement it in the Ordering module. We will also cover event stores and CQRS.