Yu Jun contributed to backend reliability and documentation accuracy across two open-source projects. For Jibing-Li/incubator-doris, Yu Jun engineered a safety-enhanced backend decommissioning flow in Java, introducing logic to skip leaky tablets and a configurable delay to prevent blocking during backend removal, thereby reducing operator intervention and aligning with distributed systems best practices. In apache/doris-website, Yu Jun improved SQL documentation by clarifying the SHOW PARTITIONS command’s WHERE clause, expanding operator support and ensuring guidance matched actual behavior. Through backend development, database management, and technical writing, Yu Jun delivered targeted, well-scoped features that addressed specific operational and developer needs.