Developed RESTful APIs using Spring Boot to support an end-to-end online visa service center application. Enhanced existing APIs by adding new features, resolving bugs, and optimizing performance, Implemented CRUD operations using MySQL database based on project requirements, ensuring seamless data management and retrieval. Conducted code analysis using SonarQube and successfully resolved security hotspots and critical issues, improving the overall code quality and security standards. Testing and Validated API responses using Postman, ensuring accurate and reliable data exchange between services, Documented APIs using Swagger, providing clear and comprehensive documentation for future reference and ease of integration. Developed robust unit test cases using JUnit and Mockito, increasing overall test coverage and ensuring code reliability. Created reports for clients using MySQL native queries and deployed them in Metabase, enabling data-driven decision-making and empowering clients to track applicant progress and trace visa status. Actively participated in the development process, following agile methodologies and delivering high-quality code within project deadlines.