Edge functions are serverless code that runs on a CDN's edge network — geographically close to the end user — instead of in a centralized region. They unlock low-latency dynamic responses globally without operating a global server fleet.
What it is
Edge functions are serverless code that runs on a CDN's edge network — geographically close to the end user — instead of in a centralized region. They unlock low-latency dynamic responses globally without operating a global server fleet.
How it actually works
Edge functions live at the same Points of Presence (PoPs) as CDN caches — 150+ locations worldwide for major providers. When a user request hits a PoP, the edge function executes there, often returning a response in 10-50ms regardless of where in the world the user is.
Common providers (2026): Cloudflare Workers (the original, most mature), Vercel Edge Functions (powered by Cloudflare under the hood), AWS Lambda@Edge (legacy but still in use), Deno Deploy, Netlify Edge Functions.
What they're good for: A/B testing assignment, geo-routing, auth checks, dynamic redirects, request rewriting, on-the-fly image optimization, server-side rendering at the edge for personalized HTML.
What they're not good for: CPU-heavy work (most edge runtimes have strict CPU time limits — 10-50ms), accessing databases that live in a single region (the latency tax kills the edge advantage), Node.js-specific code (most edge runtimes use a V8 isolate, not full Node).
Apex pattern: use edge functions for the 'hot path' of request handling (auth, geo, A/B); fall through to traditional server functions for heavier work.
At Apex IT Solutions
Our engineering team uses Edge Functions as part of standard delivery on relevant projects. Learn more about the related service: DevOps Solutions, or get a free consultation on whether this fits your project.
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