aws-lambda-functions

SKILL.md

AWS Lambda Functions

Table of Contents

Overview

When to Use

Quick Start

Reference Guides

Best Practices

Overview

AWS Lambda enables you to run code without provisioning or managing servers. Build serverless applications using event-driven triggers, pay only for compute time consumed, and scale automatically with workload.

When to Use

API endpoints and webhooks

Scheduled batch jobs and data processing

Real-time file processing (S3 uploads)

Event-driven workflows (SNS, SQS)

Microservices and backend APIs

Data transformations and ETL jobs

IoT and sensor data processing

WebSocket connections

Quick Start

Minimal working example:

# Create Lambda execution role
aws iam create-role \
  --role-name lambda-execution-role \
  --assume-role-policy-document '{
    "Version": "2012-10-17",
    "Statement": [{
      "Effect": "Allow",
      "Principal": {"Service": "lambda.amazonaws.com"},
      "Action": "sts:AssumeRole"
    }]
  }'

# Attach basic execution policy
aws iam attach-role-policy \
  --role-name lambda-execution-role \
  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

# Create function from ZIP
zip function.zip index.js
aws lambda create-function \
  --function-name my-function \
  --runtime nodejs18.x \
  --role arn:aws:iam::ACCOUNT:role/lambda-execution-role \
  --handler index.handler \
  --zip-file fileb://function.zip \
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Guide
Contents

Basic Lambda Function with AWS CLI
Basic Lambda Function with AWS CLI

Lambda Function with Node.js
Lambda Function with Node.js

Terraform Lambda Deployment
Terraform Lambda Deployment

Lambda with SAM (Serverless Application Model)
Lambda with SAM (Serverless Application Model)

Lambda Layers for Code Sharing
Lambda Layers for Code Sharing

Best Practices

✅ DO

Use environment variables for configuration

Implement proper error handling and logging

Optimize package size and dependencies

Set appropriate timeout and memory

Use Lambda Layers for shared code

Implement concurrency limits

Enable X-Ray tracing for debugging

Use reserved concurrency for critical functions

❌ DON'T

Store sensitive data in code

Create long-running operations (>15 min)

Ignore cold start optimization

Forget to handle concurrent executions

Ignore CloudWatch metrics

Use too much memory unnecessarily

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