CQRS, event sourcing, and the event streaming misconception
Modern software systems often face challenges such as scalability, flexibility, and traceability, especially in domains with complex business logic. As you learned in the previous chapters, two architectural patterns, Command Query Responsibility Segregation and Event Sourcing (CQRS+ES), have emerged as powerful tools to address these challenges.
CQRS is an architectural pattern that separates the responsibilities of commands (which represent write operations) and queries (which represent read operations). This separation allows the system to handle these operations independently, optimizing each one for its specific purpose. Unlike traditional CRUD systems, where reading and writing often share the same data model, CQRS employs distinct models for each function. Thus, commands in CQRS act as transporters of data for the aggregate, which ensures data consistency and enforces business logic during state changes. The query...
