During November 2024, Immortalety focused on backend development for the Gozargah/Marzban repository, addressing a critical issue in the subscription API. They improved API resilience by correcting HTTP status codes, ensuring that subscription errors now return 404 instead of 204, which aligns the API with expected contract behavior. Using Python and leveraging their API development expertise, Immortalety also enhanced security by removing unnecessary exception details from error responses, reducing information leakage and making client-side error handling more reliable. This targeted bug fix, while limited in scope, demonstrated careful attention to API reliability and security within a production backend environment.