Summary

In this chapter, you learned why it is important to create services that focus on user activities and how this helps teams accelerate the pace of innovation. You learned about the BFF pattern and how to combine the event sourcing and CQRS patterns to create user-facing services. And you learned how to apply the BFF pattern throughout the different phases of the data life cycle. You also learned how to implement a function-level nano architecture and how to choose between REST and GraphQL.In the next chapter, we will cover the External Service Gateway (ESG) pattern and see how it creates an anti-corruption layer that frees teams to focus on the functionality of their system. We will look at variations of the ESG pattern and cover integration with third-party systems, legacy systems, other autonomous subsystems, and more.