I have been using cloud Firestore for a month now and quite happy with how things are going so far except for the one factor and that's of course the billing. My app is a short videos app which is using too much of bandwidth. Each video is around 2MB on average. After compressing, that gets uploaded. There are around 700 users who are using the app right now and I wasn't expecting the billing to grow so much with such a small user base. The billing is still under my FREE trial and is not much for me but in future with this rate, it's sure going to empty my pocket.
I am using cloud Firestore and the storage too. My initial thought is to use another CDN network (I guess Firebase is not a CDN too) - perhaps, Bunnycdn to host the videos. Now, the question is if I switch to Bunnycdn or another CDN storage provider, will the Firebase bandwidth get reduced ? I think the high bandwidth is mainly because of videos & thus, if I switch to another hosting provider/CDN, the Firebase bandwidth won't be this high, am I correct in this approach ? Of course, there will be billing from Bunnycdn or so, but I guess their bandwidth usage price is way too affordable than Firebase.
Users upload and watch videos in the app.
So after a month of development and having discussions with the Firebase team, I moved all the data from cloud storage to a CDN provider - bunnycdn. I am not receiving any high bills from Firebase storage now. Most of my queries seem to be good and they are still under the daily limit.
If anyone finds this useful - kindly do not use Firebase storage if you are going to have high data storage and high bandwidth usage. Right now, I have only the DB collecitons and documents over firestore. All data of videos moved to bunnycdn and this is showing quite a good results to me.