Worked on the spring-kafka repository to deliver Kafka consumer startup synchronization and observability, addressing reliability and diagnostic challenges during consumer initialization. Developed a mechanism in Java that waits for all Kafka consumer threads to fully start before allowing further processing, and introduced event publishing to signal startup timeouts. This approach improved operational visibility and reduced variability in startup behavior. Enhanced test coverage by refining unit tests with Mockito, streamlining strict-mode testing, and reusing event publishing logic for failure scenarios. The work demonstrated skills in Java, Kafka, and unit testing, contributing to more robust startup orchestration and easier troubleshooting for Kafka consumers.