Summary

This chapter explored the purpose and composition of the MongoDB aggregation framework and the pipeline language you use to express data processing tasks. The chapter provided insight into how MongoDB engineers designed and implemented the aggregation framework to process data at a large scale, laying the foundations for subsequent chapters where you will learn how to build richer and more optimal aggregations than you may have done before. You also learned how to find help if you get stuck and to set up your environment to run the aggregation pipelines this book provides.

In the next chapter, you will learn about the best way to construct your aggregation pipelines for composability and robustness, which is especially important when your data structures and aggregation pipelines evolve over time, which is the nature of all modern data-centric applications.