Kafka vs EventBridge

Apache Kafka and Amazon EventBridge both serve event-driven architectures, but at different layers. Kafka is a streaming platform for high-throughput data pipelines. EventBridge is a serverless event bus for routing events between AWS services and SaaS applications.

Architecture and Routing

Kafka routes messages by topic and partition key. Consumers subscribe to topics and receive all messages. There is no content-based filtering at the broker level — consumers must filter in application code.

EventBridge routes events based on content — event source, detail-type, and any field in the event payload. Rules define patterns that match incoming events and route them to targets (Lambda, SQS, Step Functions, API Gateway, etc.). This content-based routing is EventBridge's killer feature.

Scale and Throughput

Kafka handles millions of events per second for sustained streaming workloads. It is built for data pipelines, log aggregation, and stream processing.

EventBridge is designed for event-driven orchestration at moderate scale. Default limits are around 10,000 events/sec per bus (adjustable). It is not designed for bulk data streaming but excels at routing business events between services.

Integration Model

EventBridge integrates natively with 200+ AWS services. When an S3 object is created, an EC2 instance changes state, or a CodePipeline deployment completes, EventBridge receives the event automatically. It also receives events from SaaS partners like Zendesk, Datadog, and Auth0.

Kafka integrates with external systems via Kafka Connect connectors, which are powerful but require setup and management.

When to Use Both

Many architectures use both: EventBridge for AWS service integration and event routing, with Kafka for high-throughput data streaming and processing. See our system design interview guide and event-driven architecture concepts for architectural patterns.