title: Monolith, onion architecture, multiple database types, How to do "transaction" from 2 different service classes with different database types?
body: <p>I want to ask about architecture</p>
  
  <p>I use onion architecture.
  i have 2 big modules, User Module &amp; Order Module</p>
  
  <p>The User Module uses mysql
  The Order module uses mongodb</p>
  
  <p>Both have service class.</p>
  
  <p>When a user places an order, the Service class in the order module will call the service from the User module to update the User data.</p>
  
  <p>How to do "transaction" from 2 different service classes with different database types?</p>
  
  <p>Thank you</p>