Flutter is Google’s UI toolkit for building beautiful, natively compiled applications for mobile, web, and desktop from a single codebase.

If you are planning to build a app with flutter then you can have multiple options for Backends in Flutter App. Let’s see:

  1. Firebase
  2. Dart
  3. Node.JS ( or other API )

If you want fast MVP then I would suggest FireBase. It is simple but highly effective to use. It has built it authentication, efficient database and all for small applications.

Dart as a Server Side is that popular. However, you can use Dart Language for frontend as well as backend in app development. You can create server using dart language.

You can use API of any Language like ( Node.js, Python, Java, PHP) as a backend and use flutter just to fetch the data. It is most effective approach for large applications!

I recommend to use Firebase as Backend for small application and Node.JS as Backend for Larger Application in Flutter App Development.