AWS Certified Solutions Architect – Associate (SAA-C03) — Question 164

A company provides an API to its users that automates inquiries for tax computations based on item prices. The company experiences a larger number of inquiries during the holiday season only that cause slower response times. A solutions architect needs to design a solution that is scalable and elastic.

What should the solutions architect do to accomplish this?

Answer options

• A. Provide an API hosted on an Amazon EC2 instance. The EC2 instance performs the required computations when the API request is made.
• B. Design a REST API using Amazon API Gateway that accepts the item names. API Gateway passes item names to AWS Lambda for tax computations.
• C. Create an Application Load Balancer that has two Amazon EC2 instances behind it. The EC2 instances will compute the tax on the received item names.
• D. Design a REST API using Amazon API Gateway that connects with an API hosted on an Amazon EC2 instance. API Gateway accepts and passes the item names to the EC2 instance for tax computations.

Correct answer: B

Explanation

Option B is correct because it utilizes AWS Lambda, which is inherently scalable and elastic, allowing it to handle varying loads efficiently. Options A and C rely solely on Amazon EC2 instances, which require manual scaling and may not handle peak loads effectively. Option D, while using API Gateway, still depends on a single EC2 instance, limiting scalability compared to a serverless approach with Lambda.