PixelPilot uiux-edge.instructions.md

UI/UX Edge Computing 2026

Vercel Edge Functions, Cloudflare Workers, middleware for personalization, A/B testing, and geolocation.

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1. WHEN TO USE EDGE

Edge computing runs your code closer to the user, reducing latency and enabling dynamic content without a full server hit.

• Low Latency: Speed up requests by processing them at the nearest edge node.
• Personalization: Customize content (language, currency) based on the user's location.
• A/B Testing: Split traffic between different layouts or features without client-side flickering.
• Bot Detection: Block malicious requests before they hit your origin server.

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2. A/B TESTING MIDDLEWARE (Vercel Edge)

// middleware.js (Vercel Edge Function)
import { NextResponse } from 'next/server';

export function middleware(req) {
  const cookie = req.cookies.get('ab-test-variant');
  const variant = cookie ? cookie.value : Math.random() < 0.5 ? 'A' : 'B';

  const res = NextResponse.next();

  // Set cookie for persistence
  if (!cookie) {
    res.cookies.set('ab-test-variant', variant, { path: '/' });
  }

  // Rewrite URL based on variant
  if (variant === 'B') {
    return NextResponse.rewrite(new URL('/new-layout', req.url));
  }

  return res;
}

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3. GEOLOCATION PERSONALIZATION (Cloudflare Workers)

// Cloudflare Worker Example
export default {
  async fetch(request) {
    const { country, city } = request.cf;
    
    // Customize response based on geolocation
    const response = await fetch(request);
    const body = await response.text();
    
    const personalizedBody = body.replace(
      '{{WELCOME_MESSAGE}}',
      `Welcome to our store in ${city}, ${country}!`
    );

    return new Response(personalizedBody, response);
  }
};

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4. EDGE LIMITATIONS (Free Tier)

• No Node.js APIs: Edge runtimes use a limited subset of JavaScript (no fs, child_process, etc.).
• Execution Time: Vercel free tier limits edge functions to 50ms of CPU time.
• Cold Starts: Edge functions have near-zero cold starts, but complex logic can add latency.
• Memory: Limited memory compared to traditional serverless functions.