Aws Lambda Functions

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 roleaws 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 policyaws iam attach-role-policy \  --role-name lambda-execution-role \  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
# Create function from ZIPzip function.zip index.jsaws 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:

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