This sample project demonstrates how to create a user in an Amazon Cognito User Pool, then automatically insert that user's details into a DynamoDB table once the user confirms their email. The Post Confirmation Lambda trigger handles the event from Cognito and uses the AWS SDK for JavaScript (v3) to write user data to the DynamoDB table.

Key attributes such as the user's unique ID (sub), email, and optional custom attributes are passed to Lambda, which then processes and persists this data. The table is configured in on-demand capacity mode (Pay Per Request) for cost efficiency and minimal management overhead.

This pattern deploys a Cognito User Pool, a User Pool Client, a DynamoDB table, and a Node.js AWS Lambda function as the trigger.