Worked on the thingsboard/thingsboard-gateway repository to enhance FTP workflow reliability by addressing a critical bug in file size retrieval. Focused on backend development using Python, the work involved restoring the FTP binary transfer mode (TYPE I) before executing the SIZE command after NLST, ensuring accurate file size reporting. This fix resolved issues where incorrect transfer modes led to unreliable size checks and potential data integrity problems during FTP operations. The approach included careful protocol handling, root cause analysis, and thorough documentation to safeguard against regression. The contribution improved operational stability for FTP processes without introducing new features during the period.