Describe a scenario where you would need to use both Firebase and a custom backend for deploying a Flutter application.

In a scenario where real-time data is essential, such as a chat application, combining Firestore for real-time data and a custom server for handling complex logic is a suitable approach. Firestore excels in real-time data synchronization, while a custom backend can handle more intricate business logic and computations. This hybrid approach leverages the strengths of both Firebase and a custom backend to create a robust and scalable Flutter application.