Worked on enhancing the reliability and stability of the payment validation workflow in the tf-nira/registration repository, focusing on backend improvements rather than new user-facing features. Addressed a critical bug by implementing robust error handling for external payment system responses, specifically targeting error code detection and improved traceability. Utilized Java for backend development and API integration, anchoring fixes to explicit commit references to support clearer debugging and maintenance. The work emphasized strengthening the system’s error visibility and debugging readiness, ensuring that payment validation processes are more resilient to external failures and easier to monitor and troubleshoot in production environments.