Before we can focus on the frontend side, we need to prepare a backend application in the main NX mono repository, which we're going to use.

Let's start creating a new one. Then, we're adding an empty NestJS application.

npx create-nx-workspace # I've selected None as stack and Integrated Monorepo 
# cd into the created directory
yarn add -D @nx/nest
yarn nx g @nx/nest:app apps/backend

The created application should contain a few unnecessary files. Since we have our application code ready, I will remove 

---
title: Migrating backend app to NX
description: How to migrate simple existing applications to NX
code: https://gitlab.com/fullstackio/books/newline-course-apps/building-angular-applications-with-nx-app/-/tree/main/manuscript/code/04.03-migration?ref_type=heads
privateVideoUrl: https://stream.mux.com/sTF2o1biO7S00YTKwNAwI7ZN8bgOJQaWS1EIiGyXE62A.m3u8
---

Before we can focus on the frontend side, we need to prepare a backend application in the main NX mono repository, which we're going to use.

Let's start creating a new one. Then, we're adding an empty NestJS application.

```bash
npx create-nx-workspace # I've selected None as stack and Integrated Monorepo 
# cd into the created directory
yarn add -D @nx/nest
yarn nx g @nx/nest:app apps/backend
```

The created application should contain a few unnecessary files. Since we have our application code ready, I will remove `main.ts` and the whole `app/` directory.

![Folder structure of empty NestJS application](https://d2uusema5elisf.cloudfront.net/courses/building-angular-applications-with-nx/module_05/lesson_05.03/public/images/04-03-01.png)

galczo5

How to migrate simple existing applications to NX

Migrating backend app to NX

In this lesson, we're going to migrate the backend application that I presented

to you in previous lesson to empty NX-Monarepo.

So let's start by creating an empty NX-Monarepo.

All options that I decided to choose are visible on the screen.

Everything has been installed, so now let's add necessary dependencies for NX-N

And again, we need to wait a few seconds for installation process end.

The last thing we need to do to have that empty NX-Monarepo.

Generation process has ended, so let's check what is inside our application.

So we have apps, backend, and we have our NEST.js application here.

And as you can see, the folder structure looks similar to standard NEST.js

NX tries to stick as much as it is possible to the official folder structure,

All I need to do is to delete all these files that I have here inside of the

I will simply open a C directory in my backend here.

I will copy all the files from here, and I will paste it in the app.

We have two main files, so we should deal with that.

And let's check what is in the original one.

To start the backend application in our NX-Monarepo, I need to execute comment.

Yarn, NX, serve, and the name of the application.

And as you can see, everything started, and we have the same endpoints here.

So we have our hello, we have our rooms, we've get and post, and we have our

So with that simple steps, we have migrated the whole backend application to NX

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