DVA-C02 Question 10
Single answerYour development team is building a serverless application using AWS Lambda. You need to design the architecture to handle real-time user registration events and ensure that multiple downstream services (such as sending a welcome email, updating a CRM, and logging metrics) are triggered asynchronously. Which architectural pattern is the MOST appropriate for this use case?
- A
Event-driven architecture with Amazon SNS and multiple Lambda subscribers
- B
Monolithic architecture with a single Lambda function handling all downstream tasks sequentially
- C
Orchestration pattern using AWS Step Functions to coordinate downstream tasks
- D
Microservices architecture with each task deployed in separate ECS services
Show answer and explanation
Correct answer: A
Explanation
The event-driven architecture pattern is ideal for scenarios where events (such as user registration) need to trigger multiple independent downstream processes asynchronously. Using Amazon SNS as the event source ensures a scalable and decoupled fanout mechanism, where each downstream service (like sending emails or updating a CRM) can process the event independently.
- A. Correct.
This is the correct answer. An event-driven architecture with Amazon SNS allows you to fan out the user registration event to multiple downstream subscribers (such as Lambda functions) asynchronously. This decouples the services and ensures scalability and reliability.
- B. Incorrect.
This is incorrect. A monolithic architecture where a single Lambda function sequentially handles all tasks would tightly couple the services, reducing scalability and increasing latency.
- C. Incorrect.
This is incorrect. While AWS Step Functions can be used for orchestration, it is better suited for workflows with explicit control and dependency management rather than for fanout scenarios.
- D. Incorrect.
This is incorrect. While microservices are a valid architectural pattern, deploying each task as separate ECS services introduces unnecessary complexity for this use case. A serverless, event-driven approach is more suitable.