What is fastly?

Fastly is a cloud‑based content delivery network (CDN) and edge computing platform. It stores copies of your website’s files (like images, videos, scripts) on a worldwide network of servers that sit close to end users, so content can be delivered faster and more reliably.

Let's break it down

  • Edge servers: Small data centers located in many cities around the globe. They cache your content and serve it to nearby visitors.
  • Caching: When a user requests a file, Fastly checks if it already has a fresh copy on the edge server. If it does, the file is sent instantly; if not, Fastly fetches it from your origin server, stores it, and then serves it.
  • Real‑time configuration: You can change caching rules, redirects, or add custom code (VCL) instantly without waiting for a new deployment.
  • Edge compute: Small pieces of code (like JavaScript or WebAssembly) can run on the edge servers to modify requests or responses on the fly.
  • Security features: DDoS protection, web application firewall (WAF), TLS encryption, and bot mitigation are built into the platform.

Why does it matter?

  • Speed: By serving content from a location close to the user, page load times drop dramatically, improving user experience and SEO rankings.
  • Reliability: If one edge server goes down, traffic is automatically rerouted to another, keeping your site online.
  • Scalability: Fastly can handle sudden traffic spikes (e.g., product launches, viral content) without you needing to provision extra servers.
  • Security: Integrated protections reduce the risk of attacks reaching your origin servers.
  • Cost efficiency: Offloading traffic to the CDN reduces bandwidth and compute load on your own servers.

Where is it used?

Fastly powers many high‑traffic websites and services, such as:

  • Media streaming platforms (e.g., video on demand sites)
  • E‑commerce giants handling flash sales
  • News outlets delivering breaking stories worldwide
  • SaaS applications needing low‑latency API responses
  • Mobile apps that fetch assets and data from the edge
  • Gaming companies delivering patches and live updates

Good things about it

  • Lightning‑fast cache purging - changes propagate across the network in seconds.
  • Developer‑friendly - APIs, Terraform modules, and VCL let you script custom behavior.
  • Robust edge compute - run lightweight code at the edge without managing servers.
  • Strong security suite - built‑in DDoS mitigation, WAF, and TLS management.
  • Transparent analytics - real‑time logs and dashboards help you monitor performance.

Not-so-good things

  • Higher price - premium features and per‑GB pricing can be costly for small sites.
  • Complexity - mastering VCL, caching rules, and edge logic may require a learning curve.
  • Vendor lock‑in - moving away from Fastly can be difficult because of custom configurations.
  • Regional coverage gaps - while extensive, some remote locations may have fewer edge nodes, affecting performance there.
  • Support tiers - advanced support often requires an additional contract, which may be a barrier for startups.