The Smart City Information Portal is a centralized backend application developed using Spring Boot and MongoDB to manage smart city information efficiently. It provides RESTful APIs for handling user accounts, public services such as hospitals and schools, and city administrative data. The system includes a complaint management and resolution module that allows citizens to register complaints, track their status, and receive updates from city authorities, improving transparency and participation. Secure access is ensured through a role-based access control system with roles such as regular users, city administrators, and super administrators. MongoDB supports scalable and flexible data storage, while Spring Boot ensures a secure, modular, and maintainable backend architecture. The system is extensible and can be integrated with web or mobile front-end applications, supporting digital governance and improved public service delivery in smart cities. The application reduces manual effort by automating administrative workflows and ensures consistent data handling across services. It also provides a reliable foundation for future enhancements and smart city integrations.