In this chapter, we introduced the end-to-end process of developing applications with Apex, including how to create a new project, write a custom operator, assemble the DAG, integration test within the IDE, deploy the application package to the cluster, and how to navigate the distributed environment. The functionality was intentionally basic to keep the focus on the process.
Subsequent chapters will expand from here; we will cover the operators that are available in the Apex library, how to scale and tune applications, and how they are fault tolerant with exactly-once processing guarantee, as well as providing comprehensive examples that put it all together.