We (my team) are building an App where we want to have Bi-directional texting, Single Directional Picture, and audio transfer.

We are building all this using Flutter.

There will essentially be 3 apps, 2 Mobile-based (Android and iOS) and 1 Microsoft Based. We've built up most of the code already, and made a few major mistakes but fixed it(namely had no proper state management).

How things will work:

Person A has a Mobile app 1, Person A presses a button that sends a "communication request" into a Pool of requests. Person B on Desktop App chooses a "communication request" from the pool, and engages in Bi-directional texting with Person A. Person B also opens communication with Person C who is on Mobile app 2, and they engage in Bi-directional texting. Person C will be notified of communication requests through Push Notifications.

So far we've been using Socket.IO, however, I'm starting to think that's not the best.

A problem we've encountered so far is that Person A(Mobile App 1 User), is the person who sends a "communication request" into the "Communication Pool". The Mobile App 1 User, can "cancel" the communication at any point in time. When they do that, I would like for a notification to be sent to Person B, the Desktop User, For them to pick up another communication request.

I am not sure how this should be done however, should it be done in the Back-end, then how does the Front-end get notified of the change?

Any advice on which to choose?