Worked on enhancing data security in the langgenius/dify repository by implementing a sensitive token masking feature using Python. Focused on backend development and security best practices, the approach replaced the previous obfuscated masking method with a full masking solution, ensuring that sensitive token values are never partially exposed in logs or user interfaces. This change improved privacy compliance and reduced the risk of data leakage, while isolating the enhancement to minimize disruption to existing workflows. The update also facilitated easier auditability of sensitive data handling, supporting safer production operations and aligning with modern standards for secure backend engineering.