Chapter 9 — Serverless & Edge

Serverless means you write functions, not servers. The cloud provider handles all infrastructure — you pay only when your code runs.

How Serverless Works

AWS Lambda Example

// handler.js — AWS Lambda function
exports.handler = async (event) => {
    const body = JSON.parse(event.body || '{}');

    // Your business logic here
    const result = await processRequest(body);

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

// Deploy with AWS SAM or Serverless Framework:
# serverless.yml
service: myapi
provider:
  name: aws
  runtime: nodejs20.x
  region: eu-west-1
functions:
  api:
    handler: handler.handler
    events:
      - httpApi:
          path: /api/{proxy+}
          method: ANY
    memorySize: 256
    timeout: 10

Cloudflare Workers (Edge Computing)

// worker.js — runs at 300+ edge locations worldwide
export default {
  async fetch(request, env) {
    const url = new URL(request.url);

    if (url.pathname === '/api/hello') {
      return new Response(JSON.stringify({ message: 'Hello from the edge!' }), {
        headers: { 'Content-Type': 'application/json' }
      });
    }

    // Proxy to origin for other routes
    return fetch(request);
  }
};

Serverless Comparison

When Serverless Fits

Edge Computing

Edge computing runs your code at CDN points-of-presence (PoPs) close to users, reducing latency from ~100ms to ~10ms.

• Cloudflare Workers: 300+ locations, V8 isolates (not containers), near-zero cold start
• AWS CloudFront Functions: Lightweight, runs at CloudFront edge locations
• Deno Deploy: 35+ regions, TypeScript-native
• Vercel Edge Functions: Built on Cloudflare Workers