→  Designed and built 3 end-to-end backend applications (BillFlow, ClearSpend, Banking System) from scratch using Java and Spring Boot, demonstrating ability to independently ship functional systems. →  Architected RESTful APIs following a layered MVC architecture (Controller → Service → Repository), enabling clean separation of concerns and future extensibility. →  Integrated Spring Data JPA with MySQL for all three projects — designed normalized schemas, handled relational data, and implemented query filtering for date-range and category-based reports. →  Implemented automated business logic including invoice generation with quantity-based pricing (BillFlow) and monthly financial summary calculations (ClearSpend), reducing manual calculation effort. →  Applied core OOP design principles (encapsulation, abstraction, exception handling) across all projects, improving code modularity and fault tolerance for real-world transaction scenarios. →  Managed full development lifecycle using Git & GitHub — maintained version-controlled repositories, wrote structured commits, and organized project code across public repos with documentation.