Edge Function

Definitions

1. A serverless function that runs at CDN edge locations close to the user, rather than in a centralized cloud region. Executes in lightweight runtimes (V8 isolates, not full containers) with sub-millisecond cold starts. Used for authentication, A/B testing, personalization, and request rewriting. Offered by Cloudflare Workers, Vercel Edge, and Deno Deploy.

   In plain English: A tiny program that runs on servers close to the user (at the CDN edge) for ultra-fast responses.

   Example: "The auth check runs as an edge function — it validates the JWT in 2ms at the closest PoP instead of round-tripping to us-east-1."

Related Terms

• Allocator
• Big-O
• Cache
• Comptime
• Concurrency
• Frame Rate
• Cold Start
• V8 Isolate