Next.js
/Advanced
Edge Functions
Definition
Serverless functions that explicitly execute on the Edge Runtime network, providing lower latency and faster cold boots than traditional Serverless functions.
Explain Like I'm New
A traditional serverless function takes ~1 second to wake up (Cold Start) and lives in one city. An Edge function wakes up in 10 milliseconds and lives in every city on Earth.
Real World Example
Building an API that serves dynamic pricing data. Because it runs on the Edge, a user in India and a user in Brazil both get the API response in under 50ms, because the function executes in a data center blocks from their house.
Common Use Cases
- •Personalization APIs
- •Bot protection
- •Header manipulation
Terminal Output
bash / terminal
/*
Comparing Architectures:
1. Node.js Server (AWS EC2)
- Location: 1 City (e.g. New York)
- Speed: Slow for global users
- Capabilities: Full OS access, heavy tasks
2. Serverless Function (AWS Lambda)
- Location: 1 City (e.g. New York)
- Speed: Has "Cold Starts" (1-3s delay)
- Capabilities: Good for API routes, database connections
3. Edge Function (Vercel Edge)
- Location: 35+ Cities Globally (Everywhere)
- Speed: 0ms Cold Start. Instant execution.
- Capabilities: Limited. Web APIs only. No direct DB sockets.
*/
Interview Questions
basic
- Which is faster to wake up from sleep: A traditional Serverless function or an Edge function?
intermediate
- Why can't you easily connect an Edge function directly to a standard PostgreSQL database?