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How to Structure Your Backend Code in Node.js (Express.js)

Vishal Yadav on July 17, 2024

When developing a Node.js application using Express.js, structuring your codebase effectively is crucial for maintainability, scalability, and ease...
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Florian Rappl

While the micro scheme is fine, it lacks a proper repository structuring.

As an example, not aggregating the source code in a src directory is a huge misstep. You might want to use TypeScript or some other tooling (e.g., a bundler) to process your code for performance benefits. As such putting everything into the root / mixing with your tooling and tests is something you want to avoid strongly.

(You should not use CommonJS - use ESModules; especially if you really care about "maintainability, scalability, and collaboration".)

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Adesoji1

if i want to convert the javascript application in ES module to a desktop application using electronjs, how do i do it?

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Florian Rappl

Electron.js understands ESM (electronjs.org/docs/latest/tutoria...) - but if you want to only use ESM in development and another format (e.g., CommonJS) at runtime I recommend using a tool such as esbuild (which can bundle and transform).

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Chibueze Onyekpere

Thanks for the new insight.

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Vishal Yadav

using tools like Electron Packager or Electron Builder.

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Juan José Cruz Ortiz

you are wrong since the moment you want to put types to a non typed language, if want types go and do you stuff in c# or java

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Florian Rappl

My comment was independent if you like or want to use TypeScript. That was one example. Having a src directory is pretty much always helpful (as you might want to bundle for performance reasons).

Maybe instead of making useless comments it would be great to improve your knowledge about JS and its ecosystem from time to time. Might help.

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Juan José Cruz Ortiz

If you had a good understanding of js you wouldn't have to use typescript in the first place, and secondly you've obviously never worked on any big enough project where the ShitTypescript spends 2 hours making bundles for perforance reasons at every line change

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NguyenDat251

Working on a big project without needing Typescript? You are the one who sounds like you have never worked on any big one. That is Typescript's purpose: to add typing syntax for js, to let the code document itself. So when the project is scaled up, people can join and easily follow up the codebase.

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Vishal Yadav

Yeah , you are right , I'm solo freelancer! but it will help who is new in this field.

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Adesoji1

nice work, thank you for this, for a react frontend that has typescript in it, how should the folder structure be arranged?

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Florian Rappl

Just put everything in a source and write the code as-is. (e.g., then src/index.tsx instead of a index.js or src/index.js). Use a tool such as esbuild to consume the source files and transform (+ bundle) them into a dist folder (src/index.tsx and related files -> dist/app.js).

It's a standard practice that pretty much all applications today follow.

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Vishal Yadav

I will share soon!

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Ashish Shukla

That’s well said but if we are really aiming that big and complex applications, then we should use another frameworks like nestjs which provide all these things out of the box.

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Clarence Liu

I agree, this is fine for JS, but any serious project should really be using Typescript as you said, type-safe SDKs are super powerful, see Tanstack Router or others that are built with this in mind.

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Ronaldo Modesto

Very good article 💯. Structuring projects is a more difficult task than it seems because we have to think about possible developments and how they can be accommodated in the least painful way possible.
If you allow me, I would just like to make a suggestion for improvement.
The regex used to validate email is vulnerable to ReDos (Regex Denial Of Service). It would be interesting to perhaps try to replace it with another one in the article so that other people who come to read the article don't end up using this regex to validate data in real systems.
Here's a tip for readers, always validate your regex before using.
I generally use this site to check if a regex is vulnerable: devina.io/redos-checker
Once again congratulations on the article 😃

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Vishal Yadav

Thanks!

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OssiDev • Edited

I have always had a bit of a problem with this type of folder structure. I don't understand how you can modularize your code with it. You have, at the root of source directory, the typical controllers, services, repositories (application, domain and data layers) folders and inside those you have similarly named files and classes, like "customer" or "product". While the controller, the service and the repository for "customer" belong together, they aren't close to each other, so it's harder to make that connection.

I always considered it better to have a modules/ folder inside which I have the customer and product and inside those folders have layers like controllers/, services/, views/ and persistence/ or repositories/ etc. This way I can easily focus on working inside one module, and if I need to, I can easily separate it to it's own service.

A tip there is to use DDD, so that you create modules based on the bounded contexts and you can easily create microservices based on those bounded contexts. Yeah, you will have more nested folders, but you still have a more clear grouping and separating them later (if needed) is much less painful.

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Juan José Cruz Ortiz

horrible i hate it its dumb

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Omara Patrick

The code looks well organized and readable

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Vishal Yadav

Thanks!

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Ayush Kumar Shaw

Thanks for this amazing writeup, Vishal. ❤️ed it!

It'll be great if you can share a sample GitHub repo for referencing a similar project structure. Would be a great addition as a reference material.

That said, I recently came up with a backend microservice template using JavaScript, Node.js, and Express.js. Although incomplete, it's quite practical and can be used to build reliable backend services. In my template though I've taken inspiration from NestJS for their modular approach to the directory structure.

Your blog though is a great reference for me to build another template, one that corresponds to the more common way of organizing the project, the way you've portrayed here.

So again, thanks! 💯

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Vishal Yadav

Thanks, bro means lot

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Iyere Handsome(Beau) Omogbeme

Not going to lie this directory structure is archaic and for beginners who are new to expressjs. There is are far more approachable and preferable ways to structure an expressjs app, most especially when working with typescript at the backend.

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Pál András Ciocan (Andris)

Well, i came across this article through daily.dev and gosh it helps me a lot, because i'm in the middle of structuring my backend in an important project. I tried structuring based on this -> github.com/goldbergyoni/nodebestpr...
Now i realize, @vyan article is what i need to go on.
Thanks for sharing.

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James Oduor • Edited

Good job this is well done. I think for me as a beginner it's the principle. whichever approach one choses it must satisfy the principle of separation of concerns. For those criticizing I think it would be best to support your claim with a well organized and concise alternative as this presented herein rather than hate and throw things here and there. Once again good job @vyan 🇰🇪

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Bhaskar Ghale

It might have been better to dive into one of the popular start kits and explore why they are structured that way.
But this is a good one nonetheless!

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Vishal Yadav

Thanks!

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Joana Pereira

Can you share the links for those popular start kits?

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Vishal Yadav

Yeah

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Srishti Prasad

Nice insights!! @vyan

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Vishal Yadav

Thanks!

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Yogesh Joshi

I request to you if possible then create GitHub repo for us. that more help to beginner like me.

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Vishal Yadav

Yes , I will create!

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Yogesh Joshi

thank you...

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krishna-Tiwari

I think this is fine also but better folder structure might be module based. This is easier to maintain and structure.

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Vishal Yadav

Yes

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Sina HeydariNejad

thanks for all the information :) huge hug from Iran .

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Biparker

Thanks for the guide, as a beginner ejs coder, I deployed my first website to be used by my coding learner group. Will help rewrite and organize.

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Vishal Yadav

Welcome!

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Izuorah Dubem kizito

I prefer modular setup. Makes it easier to scale up or down by attaching or detaching modules

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Vishal Yadav

Cool!

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raselldev

better using per services area

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Dennis kinuthia • Edited

i've been preferring grouping related items to the point where i can copy the posts route directory into another project and it would mostly work

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Amin Jalal

hi

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Jason V. Castellano

So far so good (-:. You can add repository later for your queries and create entities for your business logic.

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Mahmoud_Walid

Oh, Thanks, This is what I was waiting for ⭐

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Vishal Yadav

Cool

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BENIKAD

Nice work here

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Vishal Yadav

Thanks!

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Prashasth Nair

Nice Explaination.

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Vishal Yadav

Thanks!

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programORdie

Very usefull! Thank you for writing this

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Vishal Yadav

Nice!

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Martin Baun

Thank you very much for another insightful and important article!

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Vishal Yadav

Welcome!

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Divyang Chhantbar

Thanks for posting Vishal , infact i am also following somewhat like this structure only and believe me it helps a lot and make it less complex for the devs to understand stuff.

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Vishal Yadav

Welcome buddy!

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Wojtek

DDD hex

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Chibueze Onyekpere

I really like this post. Let's connect

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Vishal Yadav

Yes , you can see my social handle on my profile!

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mitesh bhagwant

Please share GitHub repo.

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Vishal Yadav

I did not created GitHub for this!

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liansun96

Yoooooo

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Chibueze Onyekpere

Thank you for this. I believe well structured code will save me from a lot of headache

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Vishal Yadav

Welcome!

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Aditya Pratama

why don't you put it in the src folder

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Vishal Yadav

Because , I see most people use this way only, You can put your code in src , it will be more structured.

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Aditya Pratama • Edited

if I use express generator do I have to put it in the src folder?