DeltaStream is a serverless stream processing platform designed to simplify the creation and management of real-time streaming applications by providing a SQL interface for building pipelines and materialized views, eliminating the need for complex infrastructure. The platform supports various capabilities through its REST API and CLI, allowing users to replicate and process data across different Kafka clusters without altering the production environment. In a demonstrated use case, DeltaStream processes clickstream data by replicating events from a production Kafka cluster to a development cluster, transforming them with continuous queries, and outputting results in protobuf format. The post illustrates how users can declare stores, create databases and streams, and utilize DeltaStream's relational capabilities to perform real-time data aggregation, demonstrating its potential in building efficient stream processing applications.