AWS Lambda run code in response to events such as an HTTP request.
A lambda function (Serverless code) can defined using AWS SAM.
Every Lambda function has an IAM role associated with it. This role defines what other AWS services the function is allowed to interact with.
AWS Lambda automatically monitors Lambda functions and reports metrics through Amazon CloudWatch. To help you monitor your code as it executes, Lambda automatically tracks the number of requests, the latency per request, and the number of requests resulting in an error and publishes the associated metrics. (Select Monitoring to view the log).
You can leverage these metrics to set custom alarms with Amazon CloudWatch
The Monitoring tab will show six CloudWatch metrics:
Lambda is integrated with:
amplify function invoke <resourcename>
With the AWS SAM CLI, you can invoke Lambda functions locally.
https://aws.amazon.com/blogs/compute/working-with-aws-lambda-and-lambda-layers-in-aws-sam/