An order-processing worker consumes messages from Amazon SQS. Occasionally, the worker times out after successfully creating a payment record but before deleting the message, which causes duplicate charges during retries. Some messages also fail validation repeatedly because required fields are missing. Which two changes should the team make? Select two.

Reduce the visibility timeout so failed messages return to the queue faster.

Incorrect. Reducing visibility timeout speeds up redelivery, but it does not prevent duplicate business actions and can actually increase replay pressure. The core problem is that the payment operation must tolerate retries, and poison messages need a separate failure path.

Run only one long-lived worker instance so the queue can never be processed twice.

Incorrect. A single worker reduces availability and still does not guarantee exactly-once processing, because SQS can redeliver messages after a timeout or failure. This approach makes the system less resilient and creates a single point of failure.

Switch from a standard queue to a FIFO queue and remove all other changes.

Incorrect. FIFO queues help preserve order within a message group, but they do not remove the need for idempotent processing if the consumer times out after a partial success. They also do not replace the need for a dead-letter queue for messages that will never validate successfully.

What does this SAA-C03 question test?

Static NAT maps one inside address to one outside address.

What is the correct answer to this question?

The correct answer is: Make the payment step idempotent using a unique transaction identifier. — This scenario has two distinct problems. The duplicate charge issue is caused by SQS's at-least-once delivery model combined with a consumer that can time out after partially completing work, so the payment action must be idempotent. The repeated validation failures are poison messages, which should be routed to a dead-letter queue after a redrive policy is exceeded. Together, these changes make the queue-based workflow safe and operationally manageable. Shortening the visibility timeout does not solve duplicate processing and can make retries happen even more aggressively. Running a single worker lowers availability without guaranteeing exactly-once semantics. FIFO queues can help with ordering but do not eliminate duplicates caused by consumer retries or timeouts, and they do not address poison messages.

What should I do if I get this SAA-C03 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.