Douglas Méndez developed secure chatbot API credential handling for the UCB-TallerDeDesarrollo/TDDLab repository, focusing on strengthening authorization flows and reducing authentication errors. He integrated this feature into existing chatbot request logic using JavaScript and TypeScript, emphasizing robust error handling and maintainability. By adopting a credential management pattern, Douglas reduced unauthorized access issues and improved the overall security posture of the chatbot integration. His work enhanced the user experience by minimizing friction during authentication and laid the foundation for scalable credential management. The implementation demonstrated depth in API integration and front end development, with traceable, auditable changes linked to specific commits.