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Edge Functions

Serverless functions that execute at CDN edge locations geographically close to the user, reducing latency by processing requests near the point of origin rather than in a central data center.

Edge functions run your code on a globally distributed network of servers, typically the same infrastructure that serves cached static assets. When a user in Tokyo makes a request, the edge function executes on a server in Tokyo rather than routing to a data center in Virginia, reducing round-trip latency from hundreds of milliseconds to single digits.

Platforms like Cloudflare Workers, Vercel Edge Functions, and Deno Deploy offer edge runtimes with V8 isolates that start in microseconds. These functions are ideal for request routing, A/B test assignment, authentication checks, personalization, geolocation-based content, and API response transformation.

For growth engineering, edge functions enable low-latency personalization: assigning users to experiment variants, customizing content based on location or device, and rewriting pages dynamically. The constraint is that edge functions typically have limited compute budgets and restricted access to databases, so they work best as a lightweight processing layer that augments rather than replaces your core backend.

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