How should a subscription based app properly handle server side subscription status synchronization, ensuring a user's genuine subscription access remains fully accurate and properly up to date across several genuinely separate different devices?

Since a subscription can genuinely be renewed, upgraded, downgraded, or properly cancelled directly through the platform's own respective store rather than necessarily always through your own app itself, a genuinely robust subscription implementation typically relies on your own trusted backend server properly and directly subscribing to genuine real time server notifications from Google Play or Apple, correctly and immediately updating that specific user's own subscription status within your own backend database the instant any relevant meaningful change actually genuinely occurs, ensuring every single one of that user's own separate devices genuinely and consistently reflects the exact same accurate, fully up to date current subscription status regardless of which particular specific device the original change had actually initially occurred on.

// Backend subscribes to Google Play Real-time Developer Notifications
// or Apple's own App Store Server Notifications