Improved application security by migrating JWT authentication from symmetric to asymmetric RSA keys using Spring Security, and implemented token blacklisting via Redis to prevent reuse of revoked tokens. • Built user management features such as account blocking, password changes, and admin-only actions secured with Role-Based Access Control (RBAC). Documented REST API endpoints using Swagger. • Integrated Stripe and Robokassa payment systems, implementing payment processing for in-app currency and supporting multiple payment methods and currencies. • Created and maintained JPA entities with relationships and validation constraints, and implemented repositories and DTOs using Hibernate and Spring Data JPA. Managed database schema changes with Flyway migrations. • Built unit tests using JUnit 5 and Mockito, reducing regression incidents by 30%.

• Developed OSGi services, Sling Servlets, and Sling Models using Java within Adobe Experience Manager (AEM) to implement backend logic for a content management system. • Created editable page templates and Experience Fragments for reusable site elements, including shared navigation and footer across the site. • Resolved frontend and backend bugs in AEM components, including dialog behavior and HTL (HTML Template Language) rendering issues. • Developed custom AEM components using Java, Sling Models, and HTL (HTML Template Language) to implement reusable website functionality and dynamic content rendering.