Apache Kafka's transactions feature is designed to simplify event-driven systems by providing exactly-once guarantees, eliminating the need for manual idempotence handling. Transactions allow services interconnected with Kafka to focus on their core logic without worrying about deduplicating inputs or constructing keys for outputs. This feature enables developers to build fine-grained "micro" services that behave predictably in complex chains as they would standing alone. By leveraging transactions, developers can create reliable event-driven systems that are easier to test and maintain.