upstream backend {
    least_conn;
    server backend1.example.com;
    server backend2.example.com;
}

server {
    location / {
        proxy_pass http://backend;
    }
}

Generate a Spring Boot REST API for managing [сущность или бизнес-логика, например: product catalog, user profiles, task assignments].
Include CRUD endpoints, validation (Hibernate Validator), exception handling, DTO mapping (MapStruct or ModelMapper), and OpenAPI documentation.
Ensure security with JWT-based authentication and role-based access control (Spring Security).
Use layered architecture (Controller → Service → Repository) and follow clean code principles. Add unit tests for controller and service layers.