Every distributed backend eventually confronts a deceptively simple requirement: persist a state change in a relational database and notify an external service via an HTTP webhook or message broker. In an e-commerce checkout flow, a service inserts a record into an orders table and immediately dispatches an order.created webhook to a billing or fulfillment consumer.

Executing those two operations sequentially inside a single request handler introduces the Dual-Write Problem —one of the most common sources of silent data corruption in microservice architectures:

Commit-First Failure (Lost Events): The service commits the order to the database and then issues an HTTP POST to the webhook endpoint.…