Xuyunan worked on stabilizing workflow variable parsing within the YunaiV/ruoyi-vue-pro repository, focusing on the BpmSequentialMultiInstanceBehavior component. By overriding parsing logic in the Java-based backend, Xuyunan ensured that custom variable names were preserved and that parser input was ignored for collection expressions, directly addressing errors related to the ${coll_userList} variable. This targeted bug fix improved the reliability and predictability of multi-instance workflow executions, making troubleshooting more straightforward. The work demonstrated depth in backend development, workflow engine internals, and method overriding in Java, reflecting a careful approach to enhancing system stability rather than delivering new features.