Vishal Kumar

Dr. A.P.J. Abdul Kalam Technical University, Lucknow

Bachelor's of Technology

N/A – Present

Flexsin Inc.

Web Developer

February 1, 2023 – Present

Hopper (OTA)

April 1, 2022 – April 1, 2026

Hopper is a travel app that predicts the best times to book flights and hotels by analyzing price trends. It helps users save money by providing price forecasts, sending alerts for the best booking times, and offering personalized recommendations for travel. Created Entity classes with Hibernate mappings based on ER Diagrams to define the project's data model, ensuring efficient database interactions. Developed JPQL queries and custom finder methods to enhance data retrieval, optimize performance, and facilitate complex queries. Built the Repository layer in Spring Boot to manage data persistence with the database, ensuring data integrity and smooth communication between the application and the database. Designed and implemented the Service layer to handle core business logic, maintain clean separation of concerns, and facilitate communication between the Controller and Repository layers. Developed the Controller layer to expose RESTful API endpoints, manage HTTP requests/responses, and ensure smooth integration with the front-end. Created DTO/Payload classes to ensure smooth and consistent data transfer between different layers of the application, improving maintainability and data integrity. Implemented Spring Security with JWT Token for secure API access, enabling safe authentication and authorization mechanisms across the application. Integrated OTP-based login functionality to add an additional layer of security during user authentication, enhancing user privacy. Integrated third-party APIs for SMS, Email, and WhatsApp notifications to provide real-time communication features and improve user engagement. Generated PDF documents for reporting and user-facing content as part of business requirements, ensuring users can access key information in a well-structured format. Utilized AWS S3 services for image storage and management, ensuring scalable and reliable cloud storage solutions for media assets. Developed configuration classes to manage application-specific properties and custom configurations, enhancing flexibility and maintaining consistent application behavior across different environments. Performed data validation and implemented global exception handling to ensure data integrity, avoid errors, and maintain application stability in production. Developed complex business logic solutions tailored to meet specific project requirements, ensuring that the application met client and user needs efficiently. Conducted unit testing with JUnit and Mockito to validate application logic, ensuring functionality and reliability of individual components. Performed comprehensive API testing using Postman and Swagger to validate RESTful endpoints, ensuring they work as intended and provide expected responses. Debugged and resolved application issues, optimizing application performance, reducing bugs, and improving user experience. Collaborated with team members using Git and GitHub, ensuring smooth code integration, version control, and effective team collaboration. Leveraged Java 8 features such as Streams, Lambdas, and Optional to enhance code efficiency, readability, and maintainability, promoting modern coding practices. Implemented reactive REST APIs using Spring WebFlux with Mono and Flux to support non-blocking asynchronous processing, improving application scalability, performance, and responsiveness in microservices architecture.