Core Concepts

What Are Cloudflare Workers?

Serverless execution environment running JavaScript/WebAssembly at the edge across 340+ global data centers.

Key characteristics:

• Lightweight runtime (Node.js-like, edge-optimized)

• Multi-language support (TypeScript, Rust, C++ via WebAssembly)

• HTTP request-response model

Primary Benefits

• Global Distribution → Minimal latency (closest data center)

• Edge Processing → Faster response times

• Auto-scaling → Handles traffic spikes without manual intervention

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Storage Solutions

Cloudflare KV (Key-Value Store)

Globally distributed storage for lightweight data.

Technical specs:

• Consistency: Eventual (~60 seconds propagation)

• Best for: Configuration files, user preferences, caching

• Limitation: Potential stale reads during propagation window

R2 Object Storage

S3-compatible storage for static assets.

Integration benefits:

• Edge caching capability

• Optimized delivery through Workers

• File storage (images, videos, documents)

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Technical Limitations

Execution Constraints

• Runtime: Short-lived execution only

• WebSockets: Limited support

• File Operations: No direct file manipulation

• Development: Some features require deployment for testing

Workarounds

• Stream/transform data instead of direct file manipulation

• Use external services for long-running tasks

• Test critical features in staging environment

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Implementation Best Practices

Production Setup

• Custom Domains: Avoid worker.dev URLs (rate limits/blocking risk)

• Caching Strategy: Cache frequent requests and static assets

• Error Handling: Implement comprehensive error monitoring

KV Optimization

• Design for eventual consistency

• Use frontend caching for immediate updates

• Handle propagation delays gracefully

Performance Monitoring

• Leverage Cloudflare's observability tools

• Monitor edge response times

• Track cache hit rates

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Common Use Cases

Request Processing

• API Proxying: Fetch and serve data from backend systems

• Authentication: Handle user auth at the edge

• Dynamic Routing: Route requests based on logic/conditions

Content Delivery

• Edge Caching: Serve static content from nearest location

• Asset Optimization: Transform images/files on-the-fly

• CDN Enhancement: Add custom logic to content delivery

Data Operations

• Real-time Transforms: Process data before delivery

• Request Modification: Alter headers, routing, or responses

• Middleware Logic: Add custom processing layers

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Development Workflow

Local Development

1. Use Wrangler CLI for local testing

2. Test core logic locally

3. Deploy to staging for edge-specific features

4. Monitor performance in production

Deployment Strategy

• Test KV consistency behavior

• Validate custom domain configuration

• Confirm caching behavior

• Monitor error rates post-deployment