Intermediate LevelSoftware Engineering Principles
What is CQRS (Command Query Separation) at the architectural level?
❓ Interview Prompt: Explain CQRS (Command Query Responsibility Segregation) architecture, write model vs read model separation, eventual consistency, and performance.
CQRS (Command Query Responsibility Segregation) separates read operations (Queries) from write operations (Commands) at the system architecture level:
Architecture Benefits:
•
Independent Scaling: Scale write databases (PostgreSQL optimized for normalization) separately from read databases (ElasticSearch / Redis optimized for fast queries).
•
Optimized Data Models: Read models store denormalized JSON views tailored specifically for UI display requirements.
Code Implementation Example
typescript
// Command Model (Handles Writes & Domain Rules)
class CreateUserCommand { execute(dto: CreateUserDto) { /* Validates & Writes to SQL */ } }
// Query Model (Handles Fast Reads from Denormalized Read Store)
class GetUserProfileQuery { execute(userId: string) { /* Reads JSON from Redis */ } }💡Separating Command Write models from Query Read models in CQRS.
🎯 Interview Key Takeaway
Use CQRS to decouple complex write domain logic from high-throughput read querying requirements.
#CQRS#Architecture#Eventual Consistency#Intermediate
Back to all Software Engineering Principles Questions→