Backend Development with Deno: A Beginner's Guide

In this beginner's guide to backend development with Deno, we will explore the key features and advantages of using Deno as a runtime for building server-side applications. From its secure and modular architecture to its built-in support for TypeScript, Deno offers a refreshing alternative to traditional backend development frameworks like Node.js. Whether you are a seasoned backend developer or just starting your journey, this guide will walk you through the basics of setting up a Deno project, handling HTTP requests, and leveraging Deno's powerful module system for efficient code organization.

Backend Development with Deno: A Beginner's Guide

Backend Development with Deno: A Beginner's Guide


In recent years, JavaScript has become the go-to language for web development, both on the frontend and the backend. Traditionally, Node.js has been the dominant platform for backend development using JavaScript. However, a new player has emerged in the JavaScript backend ecosystem - Deno. Created by Ryan Dahl, the original creator of Node.js, Deno aims to address some of the shortcomings of Node.js and provide a more secure and modern runtime environment. In this beginner's guide, we will explore the basics of backend development with Deno and understand why it is gaining popularity among developers.

What is Deno?

Deno is a secure runtime for JavaScript and TypeScript that runs on the V8 JavaScript engine, just like Node.js. It was built from the ground up with a focus on security, simplicity, and modern features. Deno provides a secure sandbox environment by default, which means it restricts access to the file system, network, and environment variables unless explicitly granted. This approach helps prevent potential security vulnerabilities that can arise from allowing unrestricted access.

Key Features of Deno

Deno comes with several key features that make it an attractive choice for backend development:

  1. Secure by default: Deno provides a secure runtime environment by default, where file system, network, and environment access are restricted unless explicitly allowed. This reduces the risk of security vulnerabilities.

  2. TypeScript support: Deno has built-in support for TypeScript, a statically typed superset of JavaScript. This allows developers to write more robust and maintainable code by catching type-related errors during development.

  3. Modern JavaScript features: Deno supports modern JavaScript features, including ES modules, async/await, and top-level await. This enables developers to leverage the latest language features and write cleaner and more expressive code.

  4. Built-in package manager: Deno comes with a built-in package manager called "". It allows developers to easily import third-party modules directly from URLs without the need for a centralized package registry.

  5. Standard library: Deno provides a standard library that includes modules for common tasks such as file system manipulation, HTTP requests, and cryptography. This eliminates the need to rely on external libraries for basic functionality.

Getting Started with Deno

Before diving into backend development with Deno, you need to have Deno installed on your machine. The installation process is straightforward and can be done by following the instructions provided on the official Deno website (

Once you have Deno installed, you can start writing backend applications using Deno. Let's walk through a simple example to understand the basics.

Creating a Simple Backend Application

To create a simple backend application with Deno, follow these steps:

  1. Create a new directory for your project and navigate into it using the command line.

  2. Create a new file called server.ts and open it in your favorite code editor.

  3. In server.ts, import the required modules from the Deno standard library. For example, to import the serve function from the http module, use the following code:

import { serve } from "";
  1. Define a function called startServer that will handle the server logic. Inside the function, create a new server instance using the serve function and pass in the desired host and port:
async function startServer() {
  const server = serve({ hostname: "localhost", port: 3000 });
  console.log("Server is running on http://localhost:3000");

  for await (const request of server) {
    // Handle incoming requests here
  1. Implement the logic to handle incoming requests inside the for await loop. For example, you can send a simple "Hello, Deno!" response for every request:
async function startServer() {
  // ...

  for await (const request of server) {
    request.respond({ body: "Hello, Deno!" });
  1. Finally, call the startServer function to start the server:
  1. Save the server.ts file and return to the command line. Run the following command to start the Deno server:
deno run --allow-net server.ts

Congratulations! You have just created a simple backend application with Deno. You can now access the server by opening http://localhost:3000 in your web browser.


Deno brings a fresh perspective to backend development with its focus on security, simplicity, and modern features. Its secure by default approach, built-in TypeScript support, and modern JavaScript features make it an attractive choice for developers. With Deno, you can build robust and maintainable backend applications using JavaScript or TypeScript. As Deno continues to evolve and gain popularity, it is worth exploring and considering for your next backend project. So, why not give Deno a try and see how it can enhance your backend development experience?

Remember, this guide only scratches the surface of Deno's capabilities. There is much more to explore, including Deno's module system, testing framework, and third-party libraries. To learn more, refer to the official Deno documentation ( and start building amazing backend applications with Deno!

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