How Does OOP Fit Into Backend Development?

Just a thought, what was your first programming language? If it was JavaScript, that's not a strong OOP language, so maybe try practicing OOP with standalone applications or in languages that emphasize OOP more, like Java or C#. Also, consider that many programs don’t strictly fit into front-end or back-end categories; they can be standalone tools too.

How about creating a smart home controller? You could make a tablet app that manages all the lights in a house, allowing users to turn them on or off. You could also add functionality for the air conditioning and other appliances. This kind of project will give you a practical insight into structuring your OOP code for managing various components.

Just a heads up, OOP in JavaScript can be a bit tricky, and it doesn’t necessarily represent how OOP works in languages like Java or C++. Sometimes the classic OOP concepts fall short and have been adapted to more functional styles in practice. Don't hesitate to explore other paradigms as you learn!

You should definitely check out NestJS! It’s built on top of Express (or you can use Fastify) but is designed for scalability and uses a lot of OOP principles. It kind of changes up how you structure your backend apps. Here’s a quick sample:

```javascript
import { Controller, Get } from '@nestjs/common';

@Controller('cats')
export class CatsController {
@Get()
findAll(): string {
return 'This action returns all cats';
}
}
```

Building something with Nest would really help you see OOP in action in a real-world context!

OOP is about associating behavior with state. In backend development, when you've used Express, you've specified a chain of behaviors for handling requests. You could take an OOP approach by utilizing the Builder pattern to manage these request handlers as a state held in an object. There are also many design patterns you can explore that show how OOP can address common software problems. A quick Google search on GoF design patterns will give you plenty of ideas!