Chinh Duong Thi enhanced the nashtech-garage/yas repository by building robust integration tests for the Recommendations Service, focusing on end-to-end data synchronization using Kafka-based Change Data Capture events. Leveraging Java, Spring Boot, and Testcontainers, Chinh established a scalable, containerized testing environment with Kafka and PostgreSQL, enabling deterministic and reproducible test runs. The work included refining the vector repository’s similarity search logic to improve recommendation accuracy and performance. By aligning the testing infrastructure with CI/CD pipelines, Chinh ensured ongoing feature development could proceed with greater reliability and stability, demonstrating depth in integration testing and data-driven service validation.