The ksqlDB system is an event streaming database that uses Apache Kafka as its underlying data store. It provides a SQL-like interface for stream processing, allowing users to model events as rows and insert them into streams. Streams are topics with a strongly defined schema, and each row in the stream has additional metadata. The system uses persistent queries to transform one stream into another, which run indefinitely and manage their own processing progression. ksqlDB handles data locality by partitioning data across brokers, making it easier to process smaller slices of data. It also inherits Kafka's conflict-free consumption model, allowing multiple consumers to read from the same topic in a shared manner. The system is designed to be composable, concise, and elegant, offering a higher-productivity interface for working with Kafka without diluting its core concepts.