How does Apollo PubSub work when offline or closed?

Graphql Subscriptions with Apollo client seem to be a great choice to “live update” data in the client application with changes on the server.

But how does work when the device is offline? Will the subscription go into some kind of suspended mode and receive all published events when it is back online?

How does it work, when the user killed the app? Is there any way to keep a subscription alive in background?

I am looking for a solution to keep data in my app synced with offline and killed state in mind.
Firebase is not an option because of the required level of privacy for my users.
And queries in background with expo-background-fetch seem to be blocked until the app is in foreground.

If you have any other approach for background syncing data with apollo client, I’d love to hear about it :slight_smile: