What is the CQRS (Command Query Responsibility Segregation) pattern, and how does it fit into microservices? CQRS is a pattern that separates the read (query) operations from the write (command) operations to optimize performance, scalability, and security in systems. In microservices: ● Command Side: The microservices handling writes (e.g., creating or updating data)

re responsible for applying business logic and persisting data.

• Query Side: The microservices handling reads have an optimized, often

denormalized, view of the data to provide faster responses.

Why it's useful:

• Improves scalability by allowing reads and writes to scale independently.
• Enables optimized storage for read-heavy operations, like using a NoSQL database

for reads and a relational DB for writes.

Example: In an E-commerce system, you might separate the Order Command Service

(handling order creation) from the Order Query Service (serving read-optimized views of

order data).