NodeJS: Best Practices for Production

NodeJS: Best Practices for Production

✅ NodeJS: Best Practices for Production.✅This is an attempt to enlist the most important practices for developing and deploying on NodeJs.

I have been working on this technology for a while myself. I realize its huge potential and place in the development process. With tough competition from languages like Python and Golang, NodeJS has proven its utility in appropriate use cases.

Before I delve into the best practices 😬, I would like to do a brief introduction to what a microservice pattern is. Then take the conversation further from there.

So, what are microservices?

Microservices - also known as the microservice architecture - is an architectural style that structures an application as a collection of services that are:

  • Highly maintainable and testable
  • Loosely coupled
  • Independently deployable
  • Organized around business capabilities.

The microservice architecture enables the continuous delivery/deployment of large, complex applications. It also enables an organization to evolve its technology stack.

How to decide if you need microservices

Initially, when you are just starting out to work on your MVP, you might not need to use microservices. The Y-axis scaling might not be your agenda right now. But when the product starts to mature and sometimes too early where you have to deal with scaling, the decomposition into functional modules makes more sense as the business itself is decomposing. This will be the right point to start looking into the microservices architecture pattern.

A book that I highly recommend is by Chris Richardson here:

Microservices are most commonly considered while replacing a monolithic application that used to be pretty common until recently when containerization solutions like Docker started ruling the DevOps world. But more on that later.

It would be unfair if I continue without mentioning Domain Driven Design (DDD). It is a very popular strategy for decomposing your product into functional modules. Hence it is very useful to create microservices.

So, what is a domain as per DDD?

Each problem that you are trying to solve is a domain.

Each domain is subdivided into mutually exclusive bounded contexts. These contexts are nothing but separate areas of that particular problem.

In a microservice pattern, each bounded context correlates to a microservice. DDD patterns help you understand the complexity in the domain. For the domain model for each Bounded Context, you identify and define the 
entities, value objects, and aggregates that model your domain.

Depending on the complexity of your software you can choose the DDD principles or perform a simpler approach.

The goal is to achieve a highly cohesive and loosely coupled domain model. For that follow this approach:

This was a brief intro on the DDD. To learn more about it, I highly recommend reading Eric Evans’s excellent book

Moving on.

I hope you are holding on with me. 😜

So from here on, I will talk more about practices specific to NodeJS. And what I mean is that microservices and DDD help you benchmark the true potential of NodeJS nevertheless. It’s complete in itself. How? We will see.

Which Design Pattern to use while using NodeJs

Design Patterns are about designing software using certain standards that are known to a number of developers.

There are various design patterns we can use. I would like to introduce and/or recap for developers who already know about a pattern called the Repository Pattern.

This pattern makes it easier to separate the MVC logic while also making it easier to handle model definition and model interaction with the rest of the logic.

It consists of:

  1. Controller: It only handles the request and response and associated attributes. It will not have any business logic or model definition or model associations too. (folder name: controllers)
  2. Service: It contains business logic for your microservice. The control passes from controller to a service. It’s a 1:1 relationship between a controller and its service and a 1: many relationships between service and repositories. (folder name: services)
  3. Repository: It interacts with the models that are part of the model folder. Any query to the database through the model layer will be formed here. It will not have any business logic. (folder name: repositories)
  4. Model: It contains the model definition, associations, virtual functions (eg. in mongoose)
  5. Utilities: This will contain helper classes/functions that can be used as services. Eg: a Redis utility that has all the functions required to interact with Redis. (folder name: utilities)
  6. Test case: This will include unit test cases against controller methods to ensure maximum code coverage. (folder name: spec)

To read more on this, you can refer to this link:

Ok, Tell me about cluster modules

A single instance of Node.js runs in a single thread. To take advantage of multi-core systems, the user will sometimes want to launch a cluster of Node.js processes to handle the load.

The cluster module allows easy creation of child processes that all share server ports.

const cluster = require('cluster');
const http = require('http');
const numCPUs = require('os').cpus().length;

if (cluster.isMaster) {
  console.log(`Master ${} is running`);

  // Fork workers.
  for (let i = 0; i < numCPUs; i++) {

  cluster.on('exit', (worker, code, signal) => {
    console.log(`worker ${} died`);
} else {
  // Workers can share any TCP connection
  // In this case it is an HTTP server
  http.createServer((req, res) => {
    res.end('hello world\n');

  console.log(`Worker ${} started`);


Please note that it’s ideal to use one process per container while using Docker containerization for deployment through microservices. Hence, cluster modules aren’t useful when using docker-ization.

How to handle control flow in NodeJS

While using callbacks or promises, the following libraries could be useful:

  1. Async (
  2. Vasync( with better tracking of operation)
  3. Bluebird ( handle promises eg. Promise.all etc.)

And Loops?

  • Series loop: executing each step one by one in order
async (items) => {
   for (let i = 0; i < items.length; i++) {
   const result = await db.get(items[i]);

**Series-loop.js **

  • Delayed loop: loop with a timeout
const randForTen = async() => {
   let results = [];
   for (let i = 0; i < 10; i++) {
      await timeoutPromise(1000);
  return results;


  • Parallel loop: collecting all promises in a loop and execute in parallel
async (items) => { 
      let promises = []; 
      for (let i = 0; i < items.length; i++) { 
   const results = await Promise.all(promises);  


And what are some useful linting tools?

Linting tools analyze your code statically (without running it). They identify potential bugs or dangerous patterns. Patterns like the use of undeclared variables, or “case” statements inside a switch without a “break” statement.

Enabling strict mode on your codebase with ‘use strict’ can help your code fail fast if the JavaScript parser can identify a leaked global or similar bad behaviour.

Examples of linters are Javascript lint and JS lint.

Ok, how do we handle Logging?

Some commonly used npm packages are:

  • Winston (
  • Bunyan (

Possible logging format:

{ "message": "some message", "timestamp": "2013-12-11T08:01:45.000Z",  
"version": "1", "host": "cdenza", "clientip": "", "ident": "-", 
"auth": "-", "verb": "GET", "request": "/xampp/status.php", "httpversion":  
"1.1", "response": "200"}


For distributed systems like microservices, you would like to explore distributed tracing using ZipKin etc.

A note on NPM packages : You should use a package only if it solves a problem for you that you can’t solve yourself. Regularly perform npm audits to find critical issues with your npm dependencies.

Handling uncaught exceptions

By default, Node.js handles such exceptions by printing the stack trace to stderr and exiting with code 1, overriding any previously set process.exitCode

Note: Adding a handler for the 'uncaughtException' event overrides this default behaviour.

Alternatively, change the process.exitCode in the 'uncaughtException' handler which will result in the process exiting with the provided exit code. Otherwise, in the presence of such a handler, the process will exit with 0.

process.exit(0) – successful termination
process.exit(1) – unsuccessful termination

Handling unhandled rejections

Promises are ubiquitous in Node.js code and sometimes chained to a very long list of functions that return promises and so on.

Not using a proper .catch(…) rejection handler will cause an unhandledRejection event to be emitted. If not properly caught and inspected, you may rob yourself of your only chance to detect and possibly fix the problem.

Extra Tip:

console.time() and console.timeEnd()

The console object has time() and timeEnd() methods that help with analyzing the performance of pieces of your code.

console.time("Time this"); 
for (var i = 0; i < 10000; i++) { // Your stuff here }  
console.timeEnd("Time this");


This is not a solution for production but it can be used when you don’t have better tools.

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Top 7 Most Popular Node.js Frameworks You Should Know

Top 7 Most Popular Node.js Frameworks You Should Know

Node.js is an open-source, cross-platform, runtime environment that allows developers to run JavaScript outside of a browser. In this post, you'll see top 7 of the most popular Node frameworks at this point in time (ranked from high to low by GitHub stars).

Node.js is an open-source, cross-platform, runtime environment that allows developers to run JavaScript outside of a browser.

One of the main advantages of Node is that it enables developers to use JavaScript on both the front-end and the back-end of an application. This not only makes the source code of any app cleaner and more consistent, but it significantly speeds up app development too, as developers only need to use one language.

Node is fast, scalable, and easy to get started with. Its default package manager is npm, which means it also sports the largest ecosystem of open-source libraries. Node is used by companies such as NASA, Uber, Netflix, and Walmart.

But Node doesn't come alone. It comes with a plethora of frameworks. A Node framework can be pictured as the external scaffolding that you can build your app in. These frameworks are built on top of Node and extend the technology's functionality, mostly by making apps easier to prototype and develop, while also making them faster and more scalable.

Below are 7of the most popular Node frameworks at this point in time (ranked from high to low by GitHub stars).


With over 43,000 GitHub stars, Express is the most popular Node framework. It brands itself as a fast, unopinionated, and minimalist framework. Express acts as middleware: it helps set up and configure routes to send and receive requests between the front-end and the database of an app.

Express provides lightweight, powerful tools for HTTP servers. It's a great framework for single-page apps, websites, hybrids, or public HTTP APIs. It supports over fourteen different template engines, so developers aren't forced into any specific ORM.


Meteor is a full-stack JavaScript platform. It allows developers to build real-time web apps, i.e. apps where code changes are pushed to all browsers and devices in real-time. Additionally, servers send data over the wire, instead of HTML. The client renders the data.

The project has over 41,000 GitHub stars and is built to power large projects. Meteor is used by companies such as Mazda, Honeywell, Qualcomm, and IKEA. It has excellent documentation and a strong community behind it.


Koa is built by the same team that built Express. It uses ES6 methods that allow developers to work without callbacks. Developers also have more control over error-handling. Koa has no middleware within its core, which means that developers have more control over configuration, but which means that traditional Node middleware (e.g. req, res, next) won't work with Koa.

Koa already has over 26,000 GitHub stars. The Express developers built Koa because they wanted a lighter framework that was more expressive and more robust than Express. You can find out more about the differences between Koa and Express here.


Sails is a real-time, MVC framework for Node that's built on Express. It supports auto-generated REST APIs and comes with an easy WebSocket integration.

The project has over 20,000 stars on GitHub and is compatible with almost all databases (MySQL, MongoDB, PostgreSQL, Redis). It's also compatible with most front-end technologies (Angular, iOS, Android, React, and even Windows Phone).


Nest has over 15,000 GitHub stars. It uses progressive JavaScript and is built with TypeScript, which means it comes with strong typing. It combines elements of object-oriented programming, functional programming, and functional reactive programming.

Nest is packaged in such a way it serves as a complete development kit for writing enterprise-level apps. The framework uses Express, but is compatible with a wide range of other libraries.


LoopBack is a framework that allows developers to quickly create REST APIs. It has an easy-to-use CLI wizard and allows developers to create models either on their schema or dynamically. It also has a built-in API explorer.

LoopBack has over 12,000 GitHub stars and is used by companies such as GoDaddy, Symantec, and the Bank of America. It's compatible with many REST services and a wide variety of databases (MongoDB, Oracle, MySQL, PostgreSQL).


Similar to Express, hapi serves data by intermediating between server-side and client-side. As such, it's can serve as a substitute for Express. Hapi allows developers to focus on writing reusable app logic in a modular and prescriptive fashion.

The project has over 11,000 GitHub stars. It has built-in support for input validation, caching, authentication, and more. Hapi was originally developed to handle all of Walmart's mobile traffic during Black Friday.

Node.js Tutorial for Beginners | Node.js Crash Course | Node.js Certification Training

This courseis designed for professionals who aspire to be application developers and gain expertise in building real-time, highly-scalable applications in Node.js. The following professionals can go for this course :

Why learn Node.js?

Node.js uses JavaScript - a language known to millions of developers worldwide - thus giving it a much lower learning curve even for complete beginners. Using Node.js you can build simple Command Line programs or complex enterprise level web applications with equal ease. Node.js is an event-driven, server-side, asynchronous development platform with lightning speed execution. Node.js helps you to code the most complex functionalities in just a few lines of code...

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A Beginner Guide To Node.js (Basic Introduction To Node.js)

Node.js is a very popular javascript free and open source cross-platform for server-side programming built on Google Chrome’s Javascript V8 Engine. It is used by thousands of developers around the world to develop mobile and web applications. According to StackOverflow survey, Node.js is one of most famous choice for building the web application in 2018.


Node.js is a very popular javascript free and open source cross-platform for server-side programming built on Google Chrome’s Javascript V8 Engine. It is used by thousands of developers around the world to develop mobile and web applications. According to StackOverflow survey, Node.js is one of most famous choice for building the web application in 2018.

In this article, you will gain a deep understanding of node, learn how node.js works and why it is so popular among the developers and startups. Not In startup even big companies like eBay, Microsoft, GoDaddy, Paypal etc.

Why is Node.js so much popular

It is fast very fast

It’s a javascript runtime built on google chrome javascript v8 engine which means both node js and js executed in your browser running in the same engine that makes it very fast in comparison to any other server-side programming language.

It uses event-driven and non-blocking model

Node.js uses the event-driven, non-blocking I/O model that makes it very lightweight and efficient.
Now let’s understand the above statement in more details. Here I/O refers to Input /Output.

Event Driven Programming is a paradigm in which control flow of any program is determined by the occurrence of the events. All these events monitor by the code which is known as an event listener. If you are from javascript background then most probably you know what is event-listeners. In short, event-listener is a procedure or function that waits for an event to occurs. In javascript, onload, onclick, onblur most common event-listener.

**Blocking I/O **takes time and hence block other function. Consider the scenario where we want to fetch data from the database for two different users. Here we can not get the data of the second user until we did not complete the first user process. Since javascript is a single threaded and here we would have to start a new thread every time we want to fetch user data. So here Non-Blocking I/O parts come in.

Example of Blocking I/O operation

<span class="hljs-keyword">const</span> fs = <span class="hljs-built_in">require</span>(‘fs’);
<span class="hljs-keyword">var</span> contents = fs.readFileSync(<span class="hljs-string">'package.json'</span>).toString();
<span class="hljs-built_in">console</span>.log(contents);

In** Non-blocking I/O **operations, you can get the user2 data without waiting for the completion of the user1 request. You can initiate both requests in parallel. **Non-blocking I/O **eliminates the need for the multi-threaded, since the system can handle multiple requests at the same time. That is the main reason which makes it very fast.

Example of Non-blocking I/O operation

<span class="hljs-keyword">const</span> fs = <span class="hljs-built_in">require</span>(‘fs’);
fs.readFile(<span class="hljs-string">'package.json'</span>, <span class="hljs-function"><span class="hljs-keyword">function</span> (<span class="hljs-params">err, buf</span>)</span>{
    <span class="hljs-built_in">console</span>.log(buf.toString());

Note: You can learn more about the event loop and other things by going through this link.

What is Node Package Manager ( NPM )

It is is the official package manager for the node. It bundles automatically installed when you install node in your system. It is used to install new packages and manage them in useful ways. NPM install packages in two modes local and global. In the local mode, NPM installs packages in the node_module directory of the current working directory which location is owned by current user. Global packages installed in the directory where the node is installed and the location is owned by the root user.

What is the package.json

package.json is a plain JSON text file which manages all the packaged which you installed in your node application. Every Node.js applications should have this file at the root directory to describe the application metadata. A simple package.json file looks like below

    <span class="hljs-string">"name"</span> : <span class="hljs-string">"codesquery"</span>,
    <span class="hljs-string">"version"</span> : <span class="hljs-string">"1.0.0"'
    "repository": {
	"type" : "git",
	"url" : "github_repository_url"
    "dependencies": {
	"async": "0.8.0",
	"express": "4.2.x"

In the above file, name and versions are mandatory for the package.json file and rest is optional.

Installing Node.js

  • In Windows, you can install the node.js by using the installer provided by the official node.js website. Follow the installer instruction and node.js will be installed in your windows system.
  • In Linux OS, you can install the node.js by adding the PPA in your system and then install node js. Run the below command the terminal to install node js
sudo apt-get install curl python-software-properties
curl -sL https:<span class="hljs-comment">// | sudo -E bash -</span>
sudo apt-get install nodejs

  • In macOS, download the macOS installer from the official node.js website. Now run the installer by accepting the license and selecting the destination.

Test Node.js Installation

You can test the node.js installation by typing below command in the terminal

node -v

If node.js was installed successfully then you will see the installed version of the node in the terminal.

Frameworks and Tools

After gaining the popularity among the developers, there are so many frameworks built for the node js for the different type of uses. Here, I will tell you some of the most famous node js frameworks in the market

  • Express.js is the most popular framework for node.js development. A lot of popular websites is powered by express.js due to its lightweight.
  • Hapi.js is a powerful and robust framework for developing the API. This framework has features like input validation, configuration based functionality, error handling, caching and logging.
  • Metor.js is one of the most used frameworks in the node js web application development. This framework is backed by a huge community of developers, tutorials and good documentation.
  • is used to build a real-time web application like chat system and analytics. Its allow the bi-direction data flow between the web client and server.
  • Koa.js is yet another most used framework to build the web application using the node js. This framework is backed by the team behind Express.js. It allows you to ditch callbacks and increase error handling.


Today, Node.js shaping the future of web and application development technology. This is the just the basic of how node js works. If you want to build a scalable web application using the node js then you need to know more then this.

Till now, you have got the basic idea of node.js and now it is time to build something using the node.js. You can start with first by create a simple server using the node.js and then connect your node with MongoDB to perform the basic crud operation.