I'd like to know if anyone has a good resource that explains in technical detail how apps (e.g. banking apps) that push an authorisation message through the app to authorise certain transactions work? Something which explains the architecture end to end would be great.
E.g. Does the mobile app poll the backend in the background or are there websockets in play?
I've tried to search but many explanations are either high level functional descriptions or mainly cover generic notification architectures. Many thanks in advance.