Modern cloud platforms give developers many places to run code. The traditional serverless function model, edge functions and lightweight workers all promise scalability and low maintenance—but choosing the right option can be confusing. This article compares these deployment targets and helps you decide where your logic should live.

Table of Contents

• 1. Understanding Serverless Functions
• 2. Edge Functions: Running at the Edge
• 3. Workers and Platform Differences
• 4. Choosing the Right Deployment Target
• 5. Conclusion

1. Understanding Serverless Functions

Serverless functions are pieces of code that run on demand in the cloud. Platforms like AWS Lambda, Vercel Serverless and Netlify Functions provision the runtime, handle scaling and charge only for the compute time you use. They are usually deployed to a specific region and have a cold start cost: the provider must spin up a container the first time a request comes in. After the cold start, subsequent invocations are fast because the container stays warm for a while.

Serverless functions suit backend APIs, scheduled jobs and tasks that can tolerate a few hundred milliseconds of latency. They integrate seamlessly with other cloud services like databases and queues. Here’s an example of a simple serverless function in Next.js that returns a JSON response:

// pages/api/hello.ts
export default async function handler(req, res) {
  return res.status(200).json({ message: 'Hello from a serverless function!' });
}

2. Edge Functions: Running at the Edge

Edge functions run code on servers located physically closer to your users. Providers such as Vercel Edge Functions and Netlify Edge Functions push your logic to a global network of points of presence. Because the code executes near the user, latency is extremely low compared to a central region. Edge functions also start faster because the runtime is often a V8 isolate instead of a heavyweight container.

This environment has restrictions: you cannot install arbitrary Node.js modules or open TCP connections. Edge functions are ideal for lightweight tasks like personalization, A/B testing or request rewriting. A typical Next.js edge function looks like this:

// middleware.ts
import { NextResponse } from 'next/server';

export function middleware(request) {
  const url = request.nextUrl.clone();
  if (!url.pathname.startsWith('/blog')) {
    url.pathname = '/blog' + url.pathname;
    return NextResponse.redirect(url);
  }
  return NextResponse.next();
}

3. Workers and Platform Differences

Cloudflare Workers popularised running JavaScript at the edge using the V8 isolate model. Workers have no cold start and run in a controlled environment that restricts Node APIs but offers built‑in key‑value storage and durable objects. Workers are great for rewriting requests, caching API responses and handling authentication.

Each provider has different pricing and limits. Serverless functions typically allow more memory and CPU time but may have higher latency. Edge functions provide extremely low latency but restrict runtime capabilities. Workers sit somewhere in the middle, offering global distribution with a lightweight execution model. When evaluating a platform, consider the size of your code, the data you need to access and the response time your users expect.

4. Choosing the Right Deployment Target

Choosing between serverless, edge functions and workers depends on your use case. For heavy computation, long‑running tasks or functions that rely on Node.js modules, serverless functions in a regional data centre make sense. If you need ultra low latency or want to modify requests/responses on the fly, edge functions or workers are a better fit. Workers are particularly appealing for custom logic that needs to run on every request at the CDN level.

Sometimes you can mix and match. For example, your authentication and routing logic could run at the edge while your heavy business logic and database access live in serverless functions. Test latency and cost trade‑offs in staging before committing to a single pattern.

5. Conclusion

The cloud now offers multiple layers for executing your code. Understanding the differences between serverless functions, edge functions and workers helps you design faster and more cost‑effective applications. Consider where your users are, how much latency matters and what restrictions you can work with. Often a hybrid approach yields the best of all worlds.