Car Rental Platform
Distributed microservices system with transactional consistency via Kafka and the Outbox pattern. Built with Spring Boot, React, and Keycloak.
This distributed car rental platform was built as an engineering project applying strict test-driven development practices to a microservices architecture. The system handles fleet management, reservations, and payment processing with guaranteed transactional consistency across services.
Backend services were developed with Spring Boot and PostgreSQL, continuously validated through JUnit and ephemeral Testcontainers environments. The payment module integrates PayPal through a resilient pipeline using Kafka for event streaming, change data capture for database synchronization, and the Outbox pattern to ensure exactly-once processing semantics across service boundaries. Security is centralized through Keycloak with OAuth 2.0 and OIDC, with dynamic request routing handled by Spring Cloud Gateway. The user interface was built with React.
The result was zero transaction loss across distributed payment processes and elimination of critical regressions before deployment. The exhaustive test coverage produced a highly maintainable codebase.