lnToyStore illustrates how a more detailed and constraint-rich domain can be implemented using a clean, maintainable, and production-ready architecture. Built with Spring Boot, Angular, OAuth2/OIDC security, MySQL, Liquibase, MapStruct, and Ehcache, it highlights structured validation, relationship modeling, and pagination in a secure application flow. With its containerized Docker environment, full Keycloak integration, and Prometheus–Grafana observability, lnToyStore offers a solid foundation for exploring advanced authentication models, API interactions, and monitoring techniques within a controlled and technology-driven example.