Tag
How a duplicate-payouts report from finance taught me that idempotency is a system property, not a one-service bug fix — and the path from a tactical patch to a cross-cutting framework that took at-least-once seriously.
A UX complaint led me to one of the most underrated primitives in the Kafka client — consumer.pause(). Here's how a 2-second delay problem ruled out three reasonable approaches and ended up at a pause/resume pattern with a TaskScheduler.
Transactional outbox and Change Data Capture solve the same problem differently. The practical trade-offs, and how to decide between them for your system.
What DLQs are, why you must have one for every message consumer, and the operational patterns that keep bad messages from blocking the good ones.
Why you need a schema registry the moment you have more than one consumer, how Avro and Protobuf compare, and the compatibility rules that prevent production accidents.
Why "save to DB, then publish to Kafka" is almost always wrong, and the outbox pattern that fixes it — with real Java code, schema, and production considerations.