Your question is Sync Mobile Data Safely. 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).
You are working on a mobile app that needs to sync local user actions, settings, and offline updates back to backend services. The app can be used with weak connectivity, duplicate requests, and delayed retries, so the sync flow has to tolerate partial failures and repeated submissions.
Describe how you would manage data synchronization between the mobile app and backend servers.