Worked on enhancing the stability of the OBDS to FHIR mapping workflow in the bzkf/obds-to-fhir repository, focusing on concurrency and data processing challenges. Addressed a thread-safety issue in the version comparison logic by replacing a HashMap with a ConcurrentHashMap within the ObdsProcessor, ensuring safe concurrent access during data transformations. Additionally, simplified the branching logic to improve the robustness and clarity of the mapping pipeline. The work was implemented in Java, leveraging core concurrency constructs to support reliable multi-threaded execution. This targeted bug fix contributed to a more maintainable and resilient data processing workflow without introducing new features.