AWS Certified Solutions Architect – Associate (SAA-C03) — Question 763

A company wants to run its payment application on AWS. The application receives payment notifications from mobile devices. Payment notifications require a basic validation before they are sent for further processing.

The backend processing application is long running and requires compute and memory to be adjusted. The company does not want to manage the infrastructure.

Which solution will meet these requirements with the LEAST operational overhead?

Answer options

• A. Create an Amazon Simple Queue Service (Amazon SQS) queue. Integrate the queue with an Amazon EventBridge rule to receive payment notifications from mobile devices. Configure the rule to validate payment notifications and send the notifications to the backend application. Deploy the backend application on Amazon Elastic Kubernetes Service (Amazon EKS) Anywhere. Create a standalone cluster.
• B. Create an Amazon API Gateway API. Integrate the API with an AWS Step Functions state machine to receive payment notifications from mobile devices. Invoke the state machine to validate payment notifications and send the notifications to the backend application. Deploy the backend application on Amazon Elastic Kubernetes Service (Amazon EKS). Configure an EKS cluster with self-managed nodes.
• C. Create an Amazon Simple Queue Service (Amazon SQS) queue. Integrate the queue with an Amazon EventBridge rule to receive payment notifications from mobile devices. Configure the rule to validate payment notifications and send the notifications to the backend application. Deploy the backend application on Amazon EC2 Spot Instances. Configure a Spot Fleet with a default allocation strategy.
• D. Create an Amazon API Gateway API. Integrate the API with AWS Lambda to receive payment notifications from mobile devices. Invoke a Lambda function to validate payment notifications and send the notifications to the backend application. Deploy the backend application on Amazon Elastic Container Service (Amazon ECS). Configure Amazon ECS with an AWS Fargate launch type.

Correct answer: D

Explanation

Amazon API Gateway and AWS Lambda provide a fully managed, serverless solution for ingesting and validating incoming mobile notifications with minimal operational overhead. Deploying the long-running backend on Amazon ECS with AWS Fargate allows the company to run containers without managing the underlying EC2 instances, meeting the requirement to avoid infrastructure management while easily adjusting compute and memory resources. The other options involve self-managed nodes, EKS Anywhere, or EC2 Spot Instances, all of which increase administrative and operational complexity.