Direct Firestore call vs GCP Firestore-Node.js API

[Mohini Gangaram]

Hi,

I have gained a little knowledge in making direct calls to Firebase-> Firestore database AND creating an API in GCP for the same. But I am not sure which one would be the best solution to go ahead with. It would be great if you can help us choose the best option.

A little detail about the project:
1. It is for State Board- the US which means anytime the project should be in a position to provide the database details to other state board applications (which points that API project should be created and consumed within our platform?)

2. We just don't know if the first point will ever come into reality and any other application will need data stored from our application (because of which we have started already with making direct calls to the fire store).

3. Is there any significant pricing difference in both methods of fetching/posting data from the fire store (first method - making direct fire store store from SDK and second- writing node js backend API solution )?

4. Of course the read and write will happen only from firebase-authenticated users.

5. The front end is in Angular latest version. It is a web application for now, but might also be provided as a mobile app in the future. 

6. The project is more of a process flow type. A request/application getting created within the platform, go through different stages/statuses and before coming to an end and getting closed. Will have file uploads. 

Let me know if I should furnish more of the details for your experts to help us in choosing the best solution.

Once again, the question is, whether we should continue making the direct firestore calls for all activities within our clientside app OR switch to creating a Node.JS/C# API (indirect method) from GCP and use it within our frontend.

Thanks in advance for reading through it.

Regards,

Mohini