Your question is Push Notifications and Background Work. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Explain how you would design push notification handling and background processing in a mobile app. Cover how the app receives a push, how it processes the payload in different app states, and how you would keep background work reliable without violating OS limits.