Fastly CDN

Fastly is a premium edge cloud platform that powers some of the world's most demanding digital experiences, serving over 20% of global internet traffic including major brands like Stripe, GitHub, Shopify, and The New York Times. Unlike traditional CDNs that can take minutes or hours to propagate configuration changes, Fastly offers real-time updates in under 150 milliseconds, making it ideal for dynamic applications and high-traffic websites that require instant control.

Built on Varnish Cache technology with custom enhancements, Fastly's platform combines content delivery, edge computing, security, and observability into a single solution. The platform operates 72 strategically-placed Points of Presence (PoPs) across six continents, with multi-tier caching architecture that maintains 95%+ cache hit ratios for optimal performance.

Edge Cloud Platform Architecture

Fastly's edge cloud operates fundamentally differently from traditional CDN providers. Rather than relying on pre-configured caching rules that require lengthy propagation times, Fastly uses a real-time configuration system that allows developers to deploy changes instantly across the global network. This architecture makes Fastly particularly valuable for e-commerce platforms during flash sales, media publishers during breaking news, and SaaS applications requiring immediate cache invalidation.

The platform employs a clustered PoP architecture where each location operates multiple servers working together, providing redundancy and increased capacity compared to single-server edge locations. This design delivers consistent performance even during traffic spikes, with the platform regularly handling over 70 million requests per second across its network.

Core platform capabilities include:

• Instant Purge: Clear cached content globally in under 150 milliseconds using purge keys, surrogate keys, or URL patterns
• Real-Time Stats: Monitor traffic, cache performance, and errors with sub-second granularity through the dashboard or API
• Version Control: Test configuration changes in staging before activating, with instant rollback capability if needed
• Multi-CDN Support: Implement intelligent routing across multiple CDN providers for maximum resilience and performance

Fastly Compute - Edge Computing Platform

Beyond traditional content delivery, Fastly offers Compute@Edge, a serverless compute platform that executes custom code at the edge. Unlike competitor edge computing solutions limited to JavaScript, Fastly Compute supports multiple programming languages including Rust, JavaScript, Go, and AssemblyScript compiled to WebAssembly, providing developers with maximum flexibility and performance.

Compute@Edge applications start in under 35 microseconds (compared to 100+ milliseconds for traditional serverless), making it suitable for low-latency use cases like A/B testing, personalization, authentication, and API orchestration. Applications are isolated using WebAssembly sandboxing, eliminating cold start penalties while maintaining security.

Common edge computing use cases:

• Dynamic Content Assembly: Combine data from multiple origins and APIs to build personalized responses at the edge
• Authentication & Authorization: Validate JWT tokens, implement OAuth flows, or enforce access policies without origin round-trips
• Image Optimization: Dynamically resize, format, and compress images based on device and network conditions
• A/B Testing: Serve different content variations without impacting origin servers or requiring client-side JavaScript
• Bot Detection: Analyze request patterns and implement custom bot mitigation logic before traffic reaches your origin

Security and Protection Features

Fastly provides enterprise-grade security through its integrated Web Application Firewall (WAF) powered by Signal Sciences technology (acquired in 2020). The WAF combines signature-based detection with behavioral analysis, identifying attacks that traditional rule-based firewalls miss. It learns normal traffic patterns for your application and flags anomalies, reducing false positives while catching sophisticated threats.

DDoS protection operates at both the network (L3/L4) and application (L7) layers, with the platform capable of absorbing attacks exceeding 1 Tbps. Unlike CDNs that route traffic through scrubbing centers during attacks (adding latency), Fastly's architecture allows traffic to continue flowing through optimal edge locations even under attack conditions.

Security features include:

• Next-Gen WAF: Machine learning-based attack detection with real-time rule updates and custom rule creation
• Rate Limiting: Implement sophisticated rate limiting based on client IP, API keys, headers, or custom logic
• TLS 1.3 Support: Latest encryption standards with automated certificate provisioning and renewal via Let's Encrypt or custom certificates
• Geo-blocking: Allow or deny traffic based on country, region, or custom geographical boundaries
• IP Reputation: Integrate with threat intelligence feeds to block known malicious IP addresses automatically

Performance Optimization

Fastly's caching system provides granular control that goes far beyond basic TTL settings. Using Varnish Configuration Language (VCL), developers can implement sophisticated caching logic based on cookies, headers, request methods, or custom conditions. This level of control allows you to cache authenticated content differently per user, implement stale-while-revalidate patterns, or create complex cache key variations.

The platform supports HTTP/2 and HTTP/3 (QUIC) protocols, delivering faster page loads through multiplexing and improved congestion control. Brotli compression reduces bandwidth usage by up to 20% compared to gzip, particularly beneficial for text-based content like HTML, CSS, and JavaScript.

Image optimization happens automatically when enabled, converting images to modern formats like WebP or AVIF based on browser support, resizing to fit device screens, and applying intelligent compression that maintains quality while reducing file sizes by 50-80%. This eliminates the need for separate image optimization services.

Developer Experience and API

Fastly provides a comprehensive REST API covering every aspect of the platform, enabling full infrastructure-as-code implementations. The API supports service configuration, origin management, TLS certificate handling, purging, and real-time analytics queries. Rate limits are generous at 1,000 requests per hour for most endpoints, sufficient for continuous deployment pipelines and automation.

The platform integrates seamlessly with modern development workflows through official Terraform provider, allowing infrastructure teams to manage CDN configuration alongside other cloud resources. Fastly also offers CLI tools, SDKs for popular languages, and integrations with CI/CD platforms like GitHub Actions, GitLab CI, and CircleCI.

Development tools include:

• Local Testing Environment: Test VCL and Compute@Edge applications locally using the Fastly CLI before deploying
• Staging Services: Create separate staging configurations for testing changes before production deployment
• Version History: Access complete configuration history with the ability to compare versions and roll back instantly
• Real-Time Logs: Stream logs to external services like Datadog, Splunk, or S3 for analysis and debugging

Observability and Analytics

Unlike many CDNs that provide analytics with 5-15 minute delays, Fastly delivers real-time statistics updated every second. This granularity allows teams to detect and respond to issues immediately rather than discovering problems through user complaints or delayed monitoring alerts.

The stats API provides detailed metrics including cache hit ratios, error rates, bandwidth usage, and geographic distribution of traffic. Custom dashboards can be built using these metrics to monitor specific KPIs relevant to your business, such as API endpoint performance or content popularity by region.

Analytics capabilities:

• Real-Time Dashboard: Monitor requests, bandwidth, cache performance, and errors with one-second granularity
• Historical Data: Access 90 days of historical statistics for capacity planning and trend analysis
• Origin Health Monitoring: Track origin response times and error rates to identify backend performance issues
• Edge Insights: Analyze cache key distribution, popular content, and geographic traffic patterns
• Custom Logging: Define custom log formats with VCL to capture exactly the data your team needs

Pricing Structure

Fastly uses transparent usage-based pricing with no hidden fees or traffic commit requirements. You pay for bandwidth (data transfer out), requests, and optional add-ons like the Next-Gen WAF or Image Optimizer. This model means you only pay for what you use, making Fastly accessible for projects of all sizes, though it's typically more expensive than commodity CDNs for high-traffic sites.

Pricing includes:

• Bandwidth starting at $0.12/GB (decreases with volume, reaching $0.08/GB at 10TB+/month)
• Requests at $0.0075 per 10,000 requests
• Next-Gen WAF starting at $0.005 per request
• Image Optimizer at $0.10 per 1,000 optimized images
• Free trial with $50 credit to test the platform
• No minimums, contracts, or long-term commitments required

Enterprise plans include volume discounts, premium support with dedicated account teams, custom SLAs, and access to advanced features like multi-CDN orchestration and private PoP deployments.

Ideal Use Cases

Fastly excels in scenarios where configuration flexibility, real-time updates, and performance consistency matter more than cost optimization. The platform is particularly valuable for e-commerce sites during peak sales events, media publishers handling viral traffic spikes, and SaaS applications requiring sub-50ms response times globally.

Perfect for:

• E-Commerce Platforms: Real-time cache purging during inventory updates, instant price changes, and consistent performance during flash sales
• Media & Publishing: Handling sudden traffic spikes, streaming video delivery, and instant content updates during breaking news
• SaaS Applications: Low-latency API delivery, edge authentication, and dynamic content personalization
• Enterprise Websites: Multi-region presence with consistent global performance and comprehensive security requirements
• Developers: Teams requiring programmatic control, infrastructure-as-code, and advanced customization through VCL or edge computing

Companies that prioritize developer experience and need infrastructure that can adapt as quickly as their business typically find Fastly's premium pricing justified by reduced engineering time and superior reliability. With a 100% uptime SLA for enterprise customers and sub-second configuration updates, Fastly positions itself as the platform for businesses where downtime or slow updates directly impact revenue.