@Service
public class ProductService {
    @Autowired
    private ProductRepository repository;

    public Product getProductById(Long id) {
        return repository.findById(id)
            .orElseThrow(() -> new ProductNotFoundException(id));
    }
}

@Service
public class ProductService {
    @Autowired
    private ReactiveProductRepository repository;

    public Mono<Product> getProductById(Long id) {
        return repository.findById(id)
            .switchIfEmpty(Mono.error(new ProductNotFoundException(id)));
    }
}

@Query("SELECT o FROM Order o WHERE o.userId = :userId AND o.status = :status AND o.createdDate BETWEEN :start AND :end ORDER BY o.createdDate DESC")
List<Order> findUserOrdersInDateRange(@Param("userId") Long userId, @Param("status") OrderStatus status, @Param("start") LocalDate start, @Param("end") LocalDate end);

@OneToMany(mappedBy = "order", fetch = FetchType.EAGER)
@BatchSize(size = 30)
private Set<OrderItem> items;

@Cacheable(value = "products", key = "#id")
public Mono<Product> getProductById(Long id) { ... }

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
spec:
  minReplicas: 5
  maxReplicas: 20
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 70