Java Developer

Master object-oriented design principles and patterns in Java by building a RideShare simulation from the ground up. This course covers SOLID principles, Factory, Builder, Strategy, Observer, Decorator, Adapter, and Dependency Injection patterns through hands-on refactoring exercises. Students progressively transform a monolithic codebase into a clean, extensible, pattern-driven application.

Build a production-quality Task Manager REST API from scratch using Spring Boot, Spring Data JPA, and PostgreSQL. This course covers Spring Boot fundamentals, REST controllers, service layer design, JPA persistence, Bean Validation, global exception handling, and pagination. Students incrementally build a fully functional API that serves as a portfolio piece.

Build comprehensive test coverage for Java applications using JUnit 5, Mockito, and Spring Boot's testing infrastructure. This course takes a pre-built, untested E-Commerce Order Processing System and adds tests layer by layer: unit tests, Mockito mocks, MockMvc controller tests, repository tests with @DataJpaTest, TDD with a new feature, and full integration tests with Testcontainers. By the capstone you will have a complete, professional-grade test suite.

Incrementally harden a Spring Boot Task Management API called Vaultly through seven security layers. You will start with an unsecured CRUD API and progressively add HTTP Basic authentication, form-based login with database-backed users, stateless JWT token authentication, role-based access control (RBAC) with ADMIN and USER roles, method-level security using @PreAuthorize and @PostAuthorize with SpEL expressions, and OAuth2/OpenID Connect resource server configuration using Keycloak. The capstone adds a full audit trail that records every authentication success and failure event. By the end you will have a deeply-secured, production-quality REST API that demonstrates every major Spring Security pattern.

Master the art of building high-throughput, production-ready Java applications. In this advanced course, you play the role of a senior Java engineer at FreightFlow a logistics company processing hundreds of thousands of shipment orders daily. You will profile and progressively optimize the Order Processing System through six performance transformations: concurrent thread pool execution, CompletableFuture async pipelines, HikariCP connection pooling with batch inserts, Caffeine in-memory caching, JMH microbenchmarking, and GC tuning with G1GC and ZGC. Each exercise lesson produces measurable throughput improvements, turning an 80 orders/sec sequential processor into a 3,500+ orders/sec production-grade system.