How do you choose between Kafka, Pulsar, and Kinesis for streaming?

Choosing between Kafka, Pulsar, and Kinesis for streaming depends on your project’s requirements for managed services, scalability, ecosystem integration, and operational complexity. Apache Kafka is a mature, open-source streaming platform ideal for high-throughput, low-latency use cases, but it requires significant operational effort. Apache Pulsar offers built-in multi-tenancy, tiered storage, and flexible messaging models, making it suitable for large-scale or multi-tenant environments. Amazon Kinesis is a fully managed AWS service optimized for seamless integration with AWS tools, though it has scaling limitations. Your decision hinges on whether you prioritize control, scalability, or ease of management.

For scalability and architecture, Kafka uses a partitioned log model that ensures strong ordering and high throughput, which works well for event sourcing or log aggregation. However, scaling Kafka requires manual partition management and can become complex. Pulsar’s architecture separates compute (brokers) and storage (BookKeeper), enabling independent scaling and efficient data retention via tiered storage (e.g., offloading older data to cheaper storage). Kinesis scales using shards, but resharding requires downtime, making it less flexible for unpredictable workloads. For example, a real-time fraud detection system needing low latency might choose Kafka, while a global analytics platform with long retention needs could use Pulsar’s tiered storage to reduce costs.

Ecosystem and operational considerations also play a role. Kafka has a rich ecosystem, including Kafka Connect for data integration and Kafka Streams for processing, and is widely supported by third-party tools. Managed services like Confluent Cloud simplify operations. Pulsar includes lightweight processing via Pulsar Functions and supports georeplication out of the box, reducing reliance on external tools. Kinesis integrates tightly with AWS services like Lambda and Redshift but lacks cross-cloud support. Teams wanting minimal setup might choose Kinesis for serverless pipelines, while those needing hybrid-cloud flexibility or advanced stream processing might prefer Kafka or Pulsar. For example, a startup on AWS could deploy Kinesis quickly, whereas an enterprise with on-premises infrastructure might opt for Kafka’s self-managed control.