AWS Lambda and Serverless Framework: Building Scalable Functions

AWS Lambda with Serverless Framework

Build and deploy serverless applications efficiently.

Project Setup

npm install -g serverless
serverless create --template aws-nodejs --path my-service
cd my-service
npm init -y

serverless.yml Configuration

service: my-api

provider:
  name: aws
  runtime: nodejs18.x
  region: us-east-1
  environment:
    TABLE_NAME: ${self:service}-${sls:stage}

functions:
  getUsers:
    handler: handlers/users.get
    events:
      - http:
          path: users
          method: get
          cors: true

  createUser:
    handler: handlers/users.create
    events:
      - http:
          path: users
          method: post

resources:
  Resources:
    UsersTable:
      Type: AWS::DynamoDB::Table
      Properties:
        TableName: ${self:provider.environment.TABLE_NAME}
        AttributeDefinitions:
          - AttributeName: id
            AttributeType: S
        KeySchema:
          - AttributeName: id
            KeyType: HASH

Handler Function

// handlers/users.js
const AWS = require('aws-sdk');
const dynamo = new AWS.DynamoDB.DocumentClient();

module.exports.get = async (event) => {
    const params = { TableName: process.env.TABLE_NAME };
    const result = await dynamo.scan(params).promise();

    return {
        statusCode: 200,
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(result.Items),
    };
};

Cold Start Optimization

// Keep functions warm
functions:
  myFunction:
    handler: handler.main
    warmup:
      enabled: true
      events:
        - schedule: rate(5 minutes)

Serverless architecture reduces operational overhead and scales automatically.