@Service
public class UserProcessor {
    private final ApplicationEventPublisher publisher;
 
    @Transactional
    public void registerUser(User user) {
        repository.save(user);
        publisher.publishEvent(new UserRegisteredEvent(user));
    }
 
    @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
    public void handleUserRegistration(UserRegisteredEvent event) {
        emailService.sendWelcomeEmail(event.getUser());
    }
}