Edge Computing with Cloudflare Workers

Edge runtimes move latency-sensitive checks close to users—JWT validation, geo routing, A/B assignment—without round-tripping to origin on every request.

Good edge workloads

• Auth token verification with cached JWKS
• Bot scoring and WAF-adjacent rules
• Lightweight HTML transforms (security headers injection)
• Redirect logic based on CF-IPCountry

Poor edge workloads

• Heavy database transactions
• Large file uploads
• Long-running CPU tasks without Workers Unbound billing awareness

Worker + origin pattern

export default {
  async fetch(request: Request): Promise<Response> {
    const token = request.headers.get('Authorization');
    if (!await verifyJwt(token)) return new Response('Unauthorized', { status: 401 });
    return fetch(request); // pass-through to NestJS origin
  },
};

Caching and KV

Use KV for feature flags with 60s TTL. Durable Objects for coordination—not as primary database.

Observability

Export Workers analytics to the same dashboards as origin p95. Edge errors are user-facing errors.

Edge compute complements regional APIs—it does not replace your Postgres primary.