### Challenges and solutions in building large Angular apps

In large Angular applications, developers face several significant challenges. One major issue is managing complexity. These apps have lots of components, services, and modules that all need to work together smoothly. Keeping everything organized and easy to understand can be tough, especially with a big team.

Another problem is build times. As the app grows, it can take longer and longer for changes to show up during development. This can slow down the development process and make it harder to stay productive.

Dependency management is another headache. This involves making sure all the different parts of the app work well together and play nicely with outside libraries. 

### Tool limitations

Even experienced teams can struggle with managing large Angular applications without using the right tools. Organizing numerous components, services, and modules becomes challenging without tools that aid in clarity and team collaboration. Utilizing appropriate tools is key for experienced teams to successfully navigate the complexities of large Angular projects.

### Fixing problems with NX

NX offers several benefits for managing large Angular applications. It helps reduce the time it takes to build projects and keeps code well-organized by managing dependencies and structuring code into reusable parts. This makes it easier to maintain and expand applications over time.

One of NX's strengths is its ability to speed up builds. It does this by remembering previous build results and doing multiple tasks at the same time. This saves developers time and lets them make changes quickly.

NX also comes with tools for testing and checking code quality. It works well with common testing tools and helps keep code clean and consistent. This catches mistakes early and ensures code stays high-quality.

Furthermore, NX makes it easy to work together on projects. It keeps all code and shared parts in one place, making it simpler to share code between different projects or teams. This improves teamwork, reduces problems with combining code, and makes development smoother overall.

Manage Large Angular Apps and Supercharge Development Workflows

Learn how to create and maintain Angular applications using NX. 
Designed for Angular developers, this course covers best practices, improving workflow, and migrating existing applications to NX. 
Discover how to configure tools like Cypress for end-to-end testing and Storybook for UI component development. 
By the end of this course, you will have the knowledge and experience to work comfortably with NX on a daily basis.

Next-Level Angular Apps with NX

---
title: Backend overview 
description: Presenting the current module's plan, highlighting crucial backend details for the frontend to illustrate the problem domain.
code: https://gitlab.com/fullstackio/books/newline-course-apps/building-angular-applications-with-nx-app/-/tree/main/manuscript/code/04.02-backend?ref_type=heads
privateVideoUrl: https://stream.mux.com/800wfd7sDkXXXN6KudYpSREwLM9hOuelXP5GVh1ebMYY.m3u8
---

I've prepared a simple backend application in NestJS to organize our work in this module. Suppose you have never heard of NestJS, no worries. It's pretty simple, and it looks like Angular.

The most important thing to know about any backend when you're a front-end developer is what you can get from the endpoints. In NestJS, endpoint declaration is contained in controllers. Our backend has two of them.

## Rooms

```typescript { actualFilename=../../../manuscript/code/04.02-backend/src/rooms/rooms.controller.ts endChar=971 endLine=33 startChar=0 startLine=1 statedFilename=src/rooms/rooms.controller.ts url=https&#x3A;//gitlab.com/fullstackio/books/building-angular-applications-with-nx/module_05/lesson_05.02/.../../manuscript/code/04.02-backend/src/rooms/rooms.controller.ts }
import {Body, Controller, Get, Post} from '@nestjs/common';
import {map, Observable} from "rxjs";
import {RoomsDao} from "./db/rooms-dao";
import {RoomConverterService} from "./room-converter/room-converter.service";
import {RoomDtoConverterService} from "./room-dto-converter/room-dto-converter.service";
import {RoomDto} from "./dtos/roomDto";

@Controller('rooms')
export class RoomsController {

    constructor(
        private readonly dao: RoomsDao,
        private readonly roomConverter: RoomConverterService,
        private readonly roomDtoConverter: RoomDtoConverterService
    ) {
    }

    @Get()
    getRooms(): Observable<Array<RoomDto>> {
        return this.dao.getRooms()
            .pipe(
                map(rooms => this.roomDtoConverter.convertMany(rooms))
            );
    }

    @Post()
    addRoom(@Body() dto: RoomDto): Observable<void> {
        const room = this.roomConverter.convert(dto);
        return this.dao.addRoom(room)
    }

}
```

There are two endpoints, one to create a new room and the second to get all created rooms. So, for example, if you send a request `GET http://localhost:3000/rooms`, it should return you a list of rooms. Notice that both endpoints use `RoomDto` as a type returned by the `GET` endpoint and `POST` request body type. Later, this type is converted to something more suitable for the domain. Data Transfer Objects are used in my backend application only to transfer data, as always should be.

Presenting the current module's plan, highlighting crucial backend details for the frontend to illustrate the problem domain.