Your question is Global State Management Architecture. 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).
How would you architect a global state management system for a large-scale application?
Discuss how state is modeled, owned, updated, synchronized, persisted, and consumed across application surfaces. Explain consistency, failure handling, observability, and how you would validate the design as usage grows.