A developer is refactoring a monolithic application into microservices. One of the services, 'cart-service', currently stores the user's shopping cart in memory on the EC2 instance. The developer wants to make the service stateless so it can scale horizontally behind an Application Load Balancer. What should the developer do?

Use an Amazon EFS file system to store the cart data as files on a shared file system.

Store the cart data in an Amazon ElastiCache cluster and have the service read and write to it.

Keep the cart in memory but increase the EC2 instance size to handle more users.

Enable sticky sessions on the Application Load Balancer so requests from a user always go to the same instance.

A developer is integrating a Lambda function with a third-party payment gateway API. The API has a rate limit of 10 requests per second, and occasionally returns 429 (Too Many Requests) or 503 (Service Unavailable) responses. The developer wants to make the integration resilient without overloading the third-party service. What should the developer implement?

Implement a circuit breaker that opens after a number of consecutive failures and stops calling the API for a cooldown period.

Increase the Lambda function's timeout to 15 minutes to allow more time for the API to respond.

Retry the request immediately up to 5 times if a 429 or 503 is received.

Cache the API response in ElastiCache and always return the cached response.

What is a primary trade-off of synchronous communication between services?

It provides immediate feedback but can introduce tight coupling and latency.

It reduces the need for timeouts and retries.

It is always faster than asynchronous communication.

It improves resilience by allowing the caller to continue without waiting.

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Domain 1Objective 1

Task 1: Develop Code for Applications Hosted on AWS DVA-C02 Practice Questions (Page 7)

Part of the Content Domain 1: Development with AWS Services domain, which accounts for 32% of the DVA-C02 exam. AWS does not publish an official question count, but from its 130-minute exam (~50–85 total, ~16–27 in this domain), expect 5–9 from this objective — we provide 38 practice questions to prepare you well beyond it. (estimate)

38questions here

8free pages

13concepts

32%of the exam

Questions 31–35

31application · medium
A developer is refactoring a monolithic application into microservices. One of the services, 'cart-service', currently stores the user's shopping cart in memory on the EC2 instance. The developer wants to make the service stateless so it can scale horizontally behind an Application Load Balancer. What should the developer do?
Select an answer first
32application · medium
A developer is integrating a Lambda function with a third-party payment gateway API. The API has a rate limit of 10 requests per second, and occasionally returns 429 (Too Many Requests) or 503 (Service Unavailable) responses. The developer wants to make the integration resilient without overloading the third-party service. What should the developer implement?
Select an answer first
33foundation · easy
What is a primary trade-off of synchronous communication between services?
Select an answer first
34foundation · easy
In API Gateway, which feature allows you to modify the request or response payload before it is sent to the backend or client?
Select an answer first
35foundation · easy
In which architectural pattern does each service decide on its own when and how to react to events, without a central coordinator?
Select an answer first

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Task 1: Develop Code for Applications Hosted on AWS DVA-C02 Practice Questions (Page 7)

Questions 31–35

What is a primary trade-off of synchronous communication between services?

In API Gateway, which feature allows you to modify the request or response payload before it is sent to the backend or client?

In which architectural pattern does each service decide on its own when and how to react to events, without a central coordinator?

Keep studying — Content Domain 1: Development with AWS Services