Will there be a situation where an old reject verdict goes to DLQ and a message with an incorrect price is never rejected?

Yes, such a situation is possible if a message with a reject verdict ends up in the Dead Letter Queue (DLQ) and is not reprocessed. In this case, the announcement with the incorrect price will remain unrejected.

To avoid this, you need to:

• Implement monitoring of the DLQ and respond promptly to the appearance of messages.
• Set up mechanisms for reprocessing messages from the DLQ.
• Ensure idempotency of processing so that reprocessing does not lead to errors.

Thus, a proper error handling architecture and DLQ will help guarantee that all reject verdicts are processed and announcements with incorrect prices are rejected.