Going Serverless Part 2 – Building a REST API with No Servers

Note: This article was originally published on November 10, 2019. Some information may be outdated.

This post continues the exploration of serverless by showing how to create a REST API using serverless functions.

What Is Serverless?

Serverless doesn't mean there's no server. It means:

• You don't manage the server.
• You write functions that respond to HTTP events.
• They scale automatically and only run when called.

Example Project: Guestbook API

Create an API to:

• GET /entries - fetch all guestbook entries
• POST /entries - add a new entry

Option 1: Netlify Functions

1. Setup

npm install netlify-cli -g
netlify init
netlify functions:create

Create a file at netlify/functions/entries.js:

exports.handler = async (event) => {
  if (event.httpMethod === "GET") {
    return {
      statusCode: 200,
      body: JSON.stringify([{ name: "Luiz", message: "Great blog!" }]),
    };
  }

  if (event.httpMethod === "POST") {
    const data = JSON.parse(event.body);
    return {
      statusCode: 201,
      body: JSON.stringify({ saved: true, data }),
    };
  }

  return { statusCode: 405 };
};

Run locally:

netlify dev

Call from front-end with fetch:

fetch("/.netlify/functions/entries")
  .then(res => res.json())
  .then(data => console.log(data));

Option 2: AWS Lambda + API Gateway

This requires more setup, but is useful for production:

• Use AWS SAM or Serverless Framework
• Define function handler and route via API Gateway
• Deploy with AWS CLI

Benefits

• No server provisioning or maintenance
• Scales automatically
• Pay per request
• Works well with static frontends (like JAMstack sites)

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Serverless is more than just a trend. It’s a solid way to build real APIs without the weight of traditional backend stacks.

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Originally published at letanure.dev