Your question is Large-Scale State Management. 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 do you handle state management in a large-scale application?
Explain how you would classify state, choose an architecture pattern, define ownership and update flows, and keep the implementation testable as the application grows. Include the trade-offs between centralized and feature-local state, and describe how API data would be integrated.