Summary
In this chapter, we made more changes to the composition roots than ever. We used a small DI package to store value factories and to fetch new instances as needed. We are also able to fetch instances that are scoped to each message or request our application receives. We also implemented a messages deduplication strategy using an inbox table.
The Transactional Outbox pattern was also implemented along with local processes to publish the messages stored in an outbox table. As a result of these updates, the reliability of messages arriving at their destinations when they should and the risk of making incorrect updates as a result of reprocessing a message has been reduced a considerable amount. The event-driven version of MallBots has become a very reliable application that is much more resilient to problems springing up compared to the original synchronous version of the application.
In the next chapter, we will cover testing. We will develop a testing strategy that includes...
