aggregateService

<?php

class UserRegistrationService
{
  private $em;
  
  private $service1;
  
  private $service2;
  
  public function register(User $user, $cardToken)
  {
    $this->em->transactional(function() {
      $this->service1->create($user);
      $this->service2->createCustomer($user, $cardToken);
    });
  }
}

service1

<?php

class UserService
{
  public function create(User $user)
  {
    $this->entityManager->persist($user);
    $this->entityManager->flush();
  }
}

service2

<?php

class StripeService
{
  public function createCustomer(User $user, $cardToken)
  {
    // Make the call to Stripe API, retrieve the customer ID, and save it
  }
}