Serverless REST API on AWS uses Amazon Cognito for user authentication, API Gateway for request routing, and Lambda functions for authorization and request handling. API Gateway invokes a Lambda Authorizer to validate Cognito tokens before routing GET and POST requests to dedicated Lambda handlers that interact with DynamoDB for data persistence. CloudWatch Logs capture execution traces from both handler functions, enabling observability across the serverless stack. This pattern demonstrates secure, scalable API design for solutions architects implementing zero-infrastructure backends with fine-grained access control. Fork this diagram on Diagrams.so to customize authentication flows, add endpoints, or integrate with your CI/CD pipeline as exportable .drawio, .svg, or .png files.