FCM Token Lifecycle

[kiritowu]

As user login to the portal, a Firebase Cloud Messaging token is requested from server/local cache.

The backend needs to store the token in database as it is needed to sent notification for user.

One user can have multiple FCM token given that they might be logged in on different devices or sessions. Additionally, FCM token may be staled as user logged out or not active after 30 days.

Appropriate logic is required to manage FCM token lifecycle to improve the delivery rate of notifications.