Serverless - AWS Lambda, Vercel Functions

Perfect — let’s go through serverless architecture for Node.js, including AWS Lambda and Vercel Functions, which are increasingly popular for scalable, event-driven apps.

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1️⃣ What is Serverless?

• Serverless = cloud provider manages servers, scaling, and infrastructure, letting you focus on code.

• You write functions that are executed on demand.

• Benefits:

  • No server management

  • Automatic scaling

  • Pay only for execution time

  • Event-driven (HTTP requests, DB triggers, cron jobs, etc.)

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2️⃣ AWS Lambda

• AWS Lambda = serverless compute service

• Supports Node.js, Python, Java, and more

a) Function Example

// handler.js
exports.handler = async (event) => {
  const name = event.queryStringParameters?.name || "World";
  return {
    statusCode: 200,
    body: JSON.stringify({ message: `Hello, ${name}!` }),
  };
};

b) Deploying Lambda

1. Package code into ZIP (or use serverless framework)

2. Upload via AWS Console or CLI

3. Connect to API Gateway for HTTP requests

c) Trigger Examples

• HTTP requests via API Gateway

• Database changes (DynamoDB streams)

• S3 uploads

• Scheduled events (cron jobs)

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3️⃣ Vercel Functions

• Serverless functions embedded in Vercel projects

• Simple file-based routing

a) Example

// api/hello.js
export default function handler(req, res) {
  const { name } = req.query;
  res.status(200).json({ message: `Hello, ${name || "World"}` });
}

• Deploy via vercel CLI → function accessible at /api/hello

• Automatically scales and runs only when called

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4️⃣ Advantages of Serverless for Node.js

1. Zero server management → focus on business logic

2. Scales automatically with traffic

3. Cost-efficient → pay-per-execution model

4. Quick deployment → no complex server setup

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5️⃣ Limitations / Considerations

Limitation	Notes
Cold starts	Function may take longer on first request
Stateless	Cannot store persistent state inside function
Execution time limits	AWS Lambda max 15 mins, Vercel 10s–60s by default
Vendor lock-in	Tied to specific cloud provider services

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6️⃣ Best Practices

• Keep functions small and focused

• Use environment variables for secrets and config

• Use async/await for non-blocking I/O

• Use API Gateway or Vercel routing for multiple endpoints

• Combine with serverless databases (DynamoDB, PlanetScale, Supabase)

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7️⃣ Key Takeaways

• Serverless = code-first, event-driven, automatically scaled

• AWS Lambda → general-purpose, production-grade serverless functions

• Vercel Functions → easy integration for frontend + backend projects

• Ideal for microservices, APIs, cron jobs, or sporadic workloads

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Next, we could cover Node.js production best practices, combining performance, monitoring, logging, security, clustering, and deployment strategies for real-world applications.

Do you want me to go there next?