Summary

In this chapter, we learned how to arrange the components that are responsible for organizing and building the features provided by the software. By looking into use cases, we grasped the fundamental principles to translate the behaviors that allow a system to meet users' goals into code. We discovered how input ports play a central role by implementing use cases and acting as middlemen, intermediating the communication flow between internal and external things. With output ports, we can express the need for data from external sources without coupling the hexagonal system with specific technologies. Finally, by using use cases and input and output ports together, we saw how the Application hexagon supports the software's automation effort.

By learning how to arrange things inside the Application hexagon, we can now combine business rules, entities, Domain services, use cases, and other components from both the Application and Domain hexagons to create fully-fledged...