NodeJs Backend Application - Folder Structure / Boilerplate
Published: 2023-02-25 00:59:24

Building a Node.js backend service can be a challenging task, especially when it comes to organizing the codebase in a way that is easy to understand and maintain. In this post, we'll explore the best folder structure and setup for working with a Node.js application for a backend service.

## Why is folder structure important?
Before we dive into the details of the folder structure, it's important to understand why it's so important. A well-organized folder structure can make it easier to:

- Understand the overall structure of the application
- Find specific files and code quickly
- Maintain the codebase over time
- Scale the application as it grows
- Without a clear folder structure, the codebase can quickly become chaotic and difficult to work with.

## The best folder structure for a Node.js backend service
So, what does the best folder structure for a Node.js backend service look like? While there's no one-size-fits-all answer to this question, there are some general principles that can guide the organization of the codebase.

### src
First and foremost, it's important to keep the source code separate from other files and directories in the project. For this reason, we'll create a src directory to hold all the source code for the application.

### config
Next, we'll create a config directory to hold configuration files for the application. This might include environment variables, database connection settings, and other configuration options.

### controllers
Controllers are responsible for handling incoming requests and sending responses back to the client. For this reason, we'll create a controllers directory to hold all the controllers for the application.

### models
Models represent the data structures used by the application. For example, if the application is interacting with a database, models might represent tables or collections in the database. We'll create a models directory to hold all the models for the application.

### routes
Routes define the endpoints for the API. We'll create a routes directory to hold all the routes for the application.

### services
Services encapsulate the business logic of the application. They might interact with models, controllers, and other parts of the codebase. We'll create a services directory to hold all the services for the application.

### utils
Finally, we'll create a utils directory to hold utility functions that are used across the application. These might include functions for error handling, validation, and other common tasks.

### Putting it all together
With these principles in mind, here's what the overall folder structure for a Node.js backend service might look like:

```tree
/
├── .env
├── .gitignore
├── package.json
├── tsconfig.json
├── src/
│   ├── app.ts
│   ├── config/
│   ├── controllers/
│   ├── models/
│   ├── routes/
│   ├── services/
│   └── utils/
└── ...
```
As you can see, this structure is designed to keep the code organized and modular, making it easier to maintain and scale the application over time. By separating concerns into different directories, it becomes easier to make changes to specific parts of the application without affecting other parts.

I would also love to recommend to you to check the following so you can start write off the bat without manually creating your own boilerplate + a lot of utility tools it provides!

- [nx.dev](https://nx.dev/)
- [lerna](https://lerna.js.org/)