Synchronous vs Asynchronous Communication

A user clicks "Place Order" in an online store. The system now has six jobs to do. It must charge the card, save the order, and send a confirmation email. It must also tell the warehouse, update the recommendations, and record analytics.

Which of these jobs should the user wait for?

The card payment and the saved order, certainly. If the payment fails, there is no order. But nobody should wait on a loading screen while a recommendation system updates.