Jan contributed to the systemd/systemd repository by enhancing the safety and observability of tmpfiles relabeling during dry-run operations. Focusing on system programming and file system management in C, Jan implemented explicit checks to ensure that no file relabeling occurs when dry-run mode is active, thereby preventing unintended file changes during testing and continuous integration. The solution included robust guard clauses and detailed debug logging to capture both relabeling actions and skipped operations, improving diagnostics and documentation. Jan’s work maintained performance by gating new code paths behind the dry-run flag, demonstrating careful attention to reliability and maintainability in critical system code.