Yinhan Yh contributed to the githubnext/discovery-agent__apache__flink repository by developing fast checkpointing and snapshot optimization for the ForSt-backed StateBackend in Apache Flink. Using Java and leveraging distributed systems and file system operations expertise, Yinhan implemented fast-copying mechanisms and new data transfer strategies to accelerate checkpoint creation and restore workflows. In addition, Yinhan addressed correctness in the ForStIncrementalSnapshotStrategy by refining the initial full checkpoint logic and introducing a forceCopy flag to control data transfer during incremental snapshots. This work improved state reliability and performance, demonstrating depth in backend development, checkpointing, and state management for production streaming workloads.