A few weeks ago I published an article about an event-driven order pipeline I built in .NET. A CTO named Andrew Tan left a comment pointing out that my outbox pattern had a gap - the polling interval was trading latency for database load, and I had no protection against multiple poller instances stepping on each other.
I fixed the outbox gap in a follow-up post. But Andrew also flagged two more things worth addressing. This is where the pipeline stands now after working through all of them.
Where we started
The original pipeline had a working outbox pattern. Orders and outbox records written in the same PostgreSQL transaction. A background service polling every 5 seconds and publishing to Kafka. Messages marked as processed after a successful publish.
It worked. But it had three gaps Andrew spotted:
