Summary

In this chapter, we learned that cloud-native systems are built on the principles of Reactive architecture. We use asynchronous, message-driven, inter-component communication to build resilient components that are responsive and elastic. Event streaming is the mechanism for inter-component communication. Components publish domain events to notify the system of their state changes. Other components consume these events to trigger their behavior and cache pertinent information in materialized views. These materialized views make components responsive by providing a dedicated cache that is continuously warmed. They act as bulkheads to make components resilient to failures in upstream components, because the latest known state is available in local storage. This effectively turns the cloud into the database by leveraging value-added cloud services, turning the database inside out, and spreading the processing across the elastic power of all the components in the system. This empowers everyday, self-sufficient, full-stack teams to build large systems composed of bounded isolated components that scale globally.