AWS Lambda Important points :

• Initially Serverless == Function as a service
• Some of the serverless services in AWS ( AWS Lambda, DynamoDB,AWS Cognito,AWS API Gateway,Amazon S3,AWS SNS & SQS,AWS Kinesis Data Firehose,Aurora Serverless,Step Functions,Fargate)
• Free Tier of 1,000,000 AWS Lambda requests and 400000 GBs of compute time
• Integration with ALB

To expose Lambda function as HTTP(s) endpoint we can use the ALB or an API Gateway. Lambda function must be registered in target group.

Lambda@Edge :

• Lambda@Edge deploy Lambda functions alongside your Cloudfront CDN
• Below are some of the use cases of Lambda@Edge

Website Security and Privacy

Dynamic web application at the edge

SEO

Intelligently route across origins and Data centers

Bot mitigation at the edge

Real Time image transformation

A/B Testing

User Authentication and Authorization

User Prioritization

User tracking and analytics

• Lambda Execution Role : Grants the Lambda function permissions to AWS services/resources.
• By default Lambda is launched outside of your VPC.
• To Launch Lambda in VPC - You must define VPC ID , the subnet and the security groups
• Lambda will create an ENI ( Elastic Network Interface ) in your subnets ( AWSLambdaVPCAccessExecutionRole)