At the beginning of the ¹OnePlace project, our team needed to decide which service to use to send bulk notifications to all users quickly and consistently. We tested some services without success and as we already used firebase we decided to implement in the beginning using Notifications by Firebase. We're having trouble updating the user's token to see if it has removed the app or not. This brought a working overhead and we were not sure if the notification had arrived at the destination. Today we use OneSignal, which did not bring reliability to the submitted notifications, nor do we need to bother with manual token updates. We ship approximately 500 thousand notifications with 100% delivery!