Apache Kafka and its related technologies are at the forefront of a paradigm shift in building modern data-centric applications, with event-driven architectures powered by Apache Kafka becoming increasingly prevalent across various industries. This shift is driven by businesses' increased digitization, the need for real-time decision-making, and advancements in stream processing technology. Stream processing views data as continuous flows to be processed continuously, enabling responsive, flexible, decoupled, and real-time applications. Kafka Streams is a stream processing library native to Apache Kafka that allows developers to build event-driven applications in Java to process data in Apache Kafka topics. It provides a versioned protocol for correct, distributed, fault-tolerant, stateful stream processing, making it an enabler of modern stream processing. The emergence of event-driven architectures powered by Apache Kafka is expected to have a significant impact on how companies utilize data, comparable to the impact of relational databases.