CQRS Pattern: Separating Reads and Writes

Issue #71:System Design Interview Roadmap

When Simple Becomes Complex

Your e-commerce platform handles thousands of product searches per second, but every product update locks the entire inventory table. Users experience search delays during flash sales, while administrators struggle with slow reporting queries. This scenario reveals a fundamental architectural tension: optimizing for reads often conflicts with optimizing for writes.

Command Query Responsibility Segregation (CQRS) transforms this problem by recognizing that reading data and writing data are fundamentally different operations with distinct performance, consistency, and scalability requirements. Rather than forcing both through a single model, CQRS separates them into specialized pathways.

[📊 DIAGRAM 1: CQRS Architecture Overview ]