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AWS Solutions Architect Associate (SAA-C02)


  • Function as a Service (FaaS)
  • Serverless
  • Auto-scaling
  • Pay per request (number of invocations) and compute time
  • Integrated with CloudWatch for monitoring
  • Not good for running containerized applications
  • Can package and deploy Lambda functions as container images


  • Increasing RAM will improve CPU and network
  • RAM: 128 MB - 10GB
  • Max execution time: 15 mins
  • Disk capacity in function container (/tmp): 512 MB
  • Environment variables: 4 KB


  • Deployment size
    • Compressed: 50MB
    • Uncompressed: 250 MB
  • If you intend to reuse code in more than one Lambda function, consider creating a Lambda Layer (a ZIP archive that contains libraries) for the reusable code. With layers, you can use libraries in your function without including them in the deployment package. Layers let you keep your deployment package small, which makes development easier. A function can use up to 5 layers at a time.


  • By default, Lambda functions operate from an AWS-owned VPC and hence have access to any public internet or public AWS API (ex. lambda functions can interact with AWS DynamoDB APIs to PutItem)
  • Once a Lambda function is VPC-enabled, all network traffic from your function is subject to the routing rules of your VPC/Subnet. If your function needs to interact with a public resource, it will need a NAT Gateway. You should only enable your functions for VPC access when you need to interact with a private resource located in a private subnet (ex. RDS database)

To enable your Lambda function to access resources inside your private VPC, you must provide VPC subnet IDs and Security Group IDs. AWS Lambda uses this information to set up ENIs.

Supported Languages

  • Node.js (JavaScript)
  • Python
  • Java
  • C#
  • Golang
  • Ruby
  • Any other language using Custom Runtime API (community supported, example Rust)

Use cases

  • Serverless thumbnail creation using S3 & Lambda
  • Serverless CRON job using EventBridge & Lambda


  • Deploy Lambda functions alongside your CloudFront CDN for computing at edge locations
  • Customize the CDN content using Lambda at the edge location (responsive)
  • No server management (Lambda is deployed globally)
  • Pay for what you use (no provisioning)
  • Can be used to modify CloudFront requests & responses
    • attachments/Pasted image 20220510194136.jpg
  • We can create a global application using Lambda@Edge where S3 hosts a static website which uses client side JS to send requests to CF which will process the request in a lambda function in that edge location to perform some operation like fetching data from DynamoDB.
    • attachments/Pasted image 20220510194430.jpg

Last updated: 2022-06-03