In this chapter, we learned that we can use Dapper's multi-mapping and multi result features to reduce database round trips to positively impact performance and allow our REST API to accept more requests per second. We learned also that forcing the client to page through the data they need to consume helps with performance as well.

We learned how to make controller action methods asynchronous and how it positively impacts the scalability of a REST API built in ASP.NET Core. We also understood that all of the I/O calls in a method and child methods need to be asynchronous to achieve scalability benefits.

We also learned how to cache data in memory to reduce the number of expensive database calls. We understand that data that is read often and rarely changed is a great case for using a cache.

Toward the end of this chapter, we learned how large objects can negatively impact performance in the garbage collection process. In terms of a web API, it is best to let ASP.NET Core handle model binding because it is very efficient. 

We will continue to focus on the backend in the next chapter and turn our attention to the topic of security.