AWS Certified Developer – Associate (DVA-C02) — Question 522

A developer is creating a stock trading application. The developer needs a solution to send text messages to application users to confirmation when a trade has been completed.

The solution must deliver messages in the order a user makes stock trades. The solution must not send duplicate messages.

Which solution will meet these requirements?

Answer options

• A. Configure the application to publish messages to an Amazon Data Firehose delivery stream. Configure the delivery stream to have a destination of each user’s mobile phone number that is passed in the trade confirmation message.
• B. Create an Amazon Simple Queue Service (Amazon SQS) FIFO queue. Use the SendMessageIn API call to send the trade confirmation messages to the queue. Use the SendMessageOut API to send the messages to users by using the information provided in the trade confirmation message.
• C. Configure a pipe in Amazon EventBridge Pipes. Connect the application to the pipe as a source. Configure the pipe to use each user’s mobile phone number as a target. Configure the pipe to send incoming events to the users.
• D. Create an Amazon Simple Notification Service (SNS) FIFO topic. Configure the application to use the AWS SDK to publish notifications to the SNS topic to send SMS messages to the users.

Correct answer: D

Explanation

Amazon SNS FIFO topics guarantee first-in-first-out delivery and message deduplication, making them perfect for sending ordered, duplicate-free SMS notifications. Amazon SQS FIFO queues do not have 'SendMessageIn' or 'SendMessageOut' APIs and are designed for message queuing rather than direct end-user SMS delivery. Amazon Data Firehose and Amazon EventBridge Pipes do not natively support direct SMS delivery to mobile numbers without integration with a notification service like SNS.