Serverless stack: API Gateway, Lambda, DynamoDB, Cognito, SQS, SNS... (things that automatically scale, you don't need to adminstration, provision)

Lambda

• Lambda scales out (not up) automatically
• Lambda functions are independent, 1 event = 1 function
• Lambda is serverless
• Lambda functions can trigger other lambda functions, 1 event can trigger many functions if functions trigger other functions
• AWS X-ray allows you to debug