Once the API is invoked by the Trigger layer, it's received by the Amazon API Gateway, which can perform traffic management, authorization and access control, validation, transformation, and monitoring followed by invoking the backend, which in this case would be hosted in AWS Lambda.

AWS Lambda is a serverless compute environment, wherein you simply upload your code (Node.js, Python, Java, or C#), define the trigger, and the rest is handled by the service. So, as in the preceding sample architecture, API Gateway will invoke the Lambda function to execute the business logic there. Within that business logic, you can perform any type of action, which is also detailed in the following section.