What is CQRS?

Command Query Responsibility Segregation (CQRS) is a design pattern that separates the concerns of writing data (commands) from reading data (queries). The application is separated into two distinct data models that can be independently designed and optimized to provide the best performance for both reads and writes. It is often combined with event sourcing—where the commands are translated into stored events, which then asynchronously feed optimized tables for querying.

CQRS is often used in mission-critical systems where performance and scalability are essential. Because the command side is often implemented as a log of events, it can be extremely valuable in industries that are subject to auditing requirements.

That’s why many companies in financial services, the public sector, and other highly regulated industries have adopted Apache Kafka® and Confluent to power their organizations using event-driven communication and real-time data integration. And on Confluent Cloud, developers can build applications that transmit events between any system, in any programming language, all on a single platform.