You are working in a big organization as a DevOps engineer. There is a monolithic application that is deployed and maintained in AWS EC2. The application needs to be redesigned to be microservices. The new serverless event-based architecture will decouple services and components so that the application becomes more extensible. You need a central AWS service to manage the events among application components and also allow you to receive events from third-party SaaS apps such as PageDuty. Which of the following AWS services would you recommend in the new architecture?

Answer options:

A.CloudWatch Event + Lambda function.
B.CloudTrail + CloudWatch Event.
C.Amazon EventBridge + AWS Step Function.
D.Amazon EventBridge + Lambda function.

Correct Answer: D
Option A is incorrect because the event management service needs to receive events from third-party SaaS apps so Amazon EventBridge is a better choice than CloudWatch Event. Amazon EventBridge uses the Amazon CloudWatch Events API, but also includes more functionality.
Option B is incorrect because the microservice architecture needs a serverless computer component so Lambda function should be included.
Option C is incorrect because Amazon EventBridge and AWS Step Function are similar and both services can simplify workflows in distributed applications. However, Lambda function should be selected to implement the application logic.
Option D is CORRECT because Amazon EventBridge can set up event rules and Lambda functions can implement various software components. EventBridge rules can invoke Lambda functions for further processing.
Reference:
https://aws.amazon.com/blogs/compute/decoupling-larger-applications-with-amazon-eventbridge/