Asynchronous Communication Patterns

Two Communication Styles

Synchronous (REST API)

Request → Response - The client sends a request and waits for an immediate response.

Frontend → HTTP Request → Backend → Process → HTTP Response → Frontend

Characteristics: Tight coupling, immediate feedback, blocking operation, simple to implement.

Asynchronous (Kafka)

Fire-and-Forget - The client sends a message and continues without waiting.

Frontend → Kafka Producer → Topic → Kafka Consumer → Backend

Characteristics: Loose coupling, eventual consistency, non-blocking, higher throughput.

When to Use Each Pattern

Use REST When:

• Immediate response required
• Simple CRUD operations
• Read queries without side effects
• Strong consistency needed

Use Kafka When:

• High throughput needed
• Decoupling producer and consumer
• Multiple consumers for same event
• Long-running operations
• Eventual consistency acceptable