Where it came from?

created by

Ryan Dahl in 2009


later on sponsored by

Inspired by

Ruby and Python

Built on top of Google's V8 javascript engine

What it solves?

Makes it easier to develop and run web applications quickly

const http = require('http')

const server = http.createServer((request, response) => {
    response.end('Hello World!')


Networking coolness not limited to http

const net = require('net')

const sockets = []

const server = net.createServer((socket) => {

    socket.on('data', data => {
        for (const target of sockets) {
            if (target === socket) continue

    socket.on('end', () => {
        const index = sockets.indexOf(socket)
        sockets.splice(index, 1)


Non-blocking I/O for high concurrency

  • Based on "libuv" async event pool library
  • There is no possibility of halting execution
  • Reduces heap allocation cost significantly for individual connections
  • Event loop exits when there is nothing left to do


and notable success stories

Everyone in the business is already familiar with the concept

Javascript is as old as the internet

JSON is a widely known and accepted data exchange format

and since it is a first class citizen in js world,

no need for additional serialization, mapping layers

Productivity boost

doing more with less code and less hardware also means less time and less money which made everyone happy


It is very easy to deploy and run your code on any platform

Package Management done right

npm founded soon after its take off and is the default standard for what it does ever since

And yet it's still competitive

Thanks to V8, it's quite efficient and performant

So it thrived!

A huge community quickly gathered around it and new ways of doing everything with javascript started flourishing from everywhere

Web Frameworks

  • Express
  • Meteor
  • Sails
  • MEAN stack
  • Derby
  • ...


  • Hapi
  • Koa
    method: 'GET',
    path: '/hello',
    handler: function (request, h) {
        return'hello world';


  • ws
  • socket.io
  • sockjs
// client side
var socket = io();
  socket.emit('chat message', $('#m').val());
  return false;

// server side
io.on('connection', function(socket){
  socket.on('chat message', function(msg){
    console.log('message: ' + msg);

Extensive toolset for development and testing

Code linting

enforcing and maintaining code quality

ESLint has 250+ available rules

Front-end revolution

  • Styling pre-processors (less, sass)
  • Task automation and bundling (grunt, gulp, webpack)
  • SPA frameworks with extensive cli support (angular, react, vue)

Electron Platform

Desktop GUI framework. Node.js for backend and Chromium for front-end.


and Controversies


which means a single node process runs only on a single core and it can't make use of any additional cpu cores

However, fortunately there are workarounds like clustering or using process managers

Hammer and nail syndrome

if all you have is a hammer, everything looks like a nail

Changing so fast

The pace for change of not only the ecosystem but also the platform might be challenging to keep up with

Lack of structure

Both in language and project levels

Runtime errors

really easy to mess up without type-safety,

requires more defensive coding, rigorous testing

Problems with the ecosysytem

packages, packages everywhere.

node_modules getting huge in size with no effort

left-pad chaos

March 2016

module.exports = leftpad;

function leftpad (str, len, ch) {
  str = String(str);

  var i = -1;

  if (!ch && ch !== 0) ch = ' ';

  len = len - str.length;

  while (++i < len) {
    str = ch + str;

  return str;

npm messing up linux systems

February 2018

'sudo npm' was changing the ownership of system files, permanently breaking the operating system.

Virus in eslint-scope

July 2018

Ownership of a popular package gets compromised and injected malicious code steals npm credentials from running machines

Platform forks

  • IO.js (2014)
  • Ayo.js (2017)

Where it goes?


new interpereter


new optimizer


getting stronger

deno: A secure TypeScript runtime on V8

Serverless Architecture

Progressive Web Applications

Thanks a lot for listening!

find me on github.com/koraytaylan

Node.JS Introduction

By Koray Taylan Davgana

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