title: CQRS - where should I place requests to external systems?
body: <p>I'm wondering where requests to external systems (to be specific: a Webservice) should be placed in a CQRS-based system.</p>
  
  <p>For example, given a system that sends a booking-request to an external flight service:
  Should this be in the domain object, in the command handler for "bookFlight"? Or should this be in a saga, as a reaction to a domain object event "flightBookingPlaced"?</p>