Outbox Pattern

In an e-commerce application, when a customer places an order, it is common to need to send an order_placed event to an event bus for further processing. A straightforward approach would be to make an entry in the order table and then publish the event synchronously. However, this raises significant concerns regarding the availability and reliability of the event bus. Message queue is unavailable while placing order For instance, what happens if the event bus is not available at the moment of publishing? In this case, one might consider rolling back the transaction in the order service to ensure that the order is not created without the corresponding event being sent. This rollback, however, introduces a delay in the user experience and creates a tight coupling between the order creation and event publishing processes. ...