AWS Certified Developer Associate DVA-C02 Practice Question

The correct approach to ensure idempotent operations is to issue a unique transaction identifier (often called an idempotency key) for each financial operation. The service stores the first result associated with that identifier and returns the same response for subsequent requests that present the same key, preventing duplicate charges. Timestamps do not guarantee idempotency because retries can reuse the same timestamp or suffer from clock skew. Checking previous HTTP status codes is unreliable because network issues can obscure responses, and status codes are not part of the retried request. AWS X-Ray provides distributed tracing and observability; it does not implement request de-duplication or idempotency.