Building Edge Applications with Cloudflare Workers

Cloudflare Workers represents a paradigm shift in how we think about backend infrastructure. Instead of deploying to regions, your code runs in 300+ locations worldwide, automatically routed to the nearest data center.

The Programming Model

Workers use the Service Worker API, familiar to frontend developers. Requests come in as Request objects, you return Response objects. No servers to manage, no containers to orchestrate.

export default {
  async fetch(request: Request, env: Env): Promise<Response> {
    const url = new URL(request.url)
    
    if (url.pathname === '/api/hello') {
      return Response.json({ message: 'Hello from the edge!' })
    }
    
    return new Response('Not found', { status: 404 })
  }
}

Storage Options

Workers KV

Key-value storage replicated globally. Great for configuration, caching, and session data.

Durable Objects

Strongly consistent coordination primitives. Perfect for WebSocket servers, collaborative editing, and rate limiting.

D1 (SQLite)

Serverless SQL database at the edge. Familiar SQL with global replication.

Architecture Patterns

1. Edge-first API - All logic at the edge, minimal origin calls
2. Hybrid - Edge for routing/auth, Workers for compute, origin for heavy lifting
3. Static + Dynamic - Pre-rendered pages with edge functions for personalization

Deployment

# Install Wrangler
npm install -g wrangler

# Create project
wrangler init my-worker

# Deploy
wrangler deploy

Conclusion

The edge is the future. Workers make it accessible today.