Java engineerswho ship servicesnot side projects.

// services/OrderService.java
@Service
@Transactional
public class OrderService {
    private final OrderRepository orderRepo;
    private final PaymentGateway paymentGateway;
    private final KafkaTemplate<String, OrderEvent> kafka;

    public OrderDto processOrder(CreateOrderCmd cmd) {
        var order = Order.create(cmd);
        orderRepo.save(order);
        paymentGateway.charge(order.paymentDetails());
        kafka.send("orders", OrderEvent.created(order));
        return OrderDto.from(order);
    }
}
// Spring Boot. Transactional. Event-driven. Type-safe.