Event-Driven Microservices

Architecture where services communicate through asynchronous events, enabling loose coupling and scalability.

High Complexity

Technologies & Tools

Apache KafkaRabbitMQAWS SQSEventStoreApache Pulsar

Architecture Flow

1

Event Production

Services produce domain events

Event PublishersDomain EventsEvent Schema
2

Event Storage

Events stored in event store/stream

Apache KafkaEventStoreMessage Queues
3

Event Consumption

Services consume and react to events

Event HandlersEvent ConsumersEvent Processors
4

Event Replay

Replay events for state reconstruction

Event SourcingCQRSProjections

Use Cases

E-commerce order processing
User activity tracking
Real-time analytics
IoT data processing
Financial transactions

Pros

Loose coupling
High scalability
Fault tolerance
Event replay capability
Real-time processing

Cons

Eventual consistency
Event ordering complexity
Debugging challenges
Event versioning
Storage growth

When to Use

High throughput requirements
Loose coupling needs
Real-time processing
Event sourcing
Asynchronous workflows

Alternatives

Synchronous communicationAPI GatewayMessage queuesEvent streaming

Performance Metrics

Latency
Low (milliseconds to seconds)
Throughput
Very High (millions of events/sec)
Scalability
Excellent
Reliability
High
Cost
Medium to High

Key Trade-offs

Eventual Consistency

Data consistency challenges across services

Scalability

Excellent horizontal scalability

Complexity

Event ordering and replay complexity

Category Information

Category
Event-Driven
Complexity Level
High