Your question is Distributed Systems System Design. 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).
Design a distributed systems solution and walk through the key components and trade-offs.
Clarify the requirements and assumptions before proposing an architecture. Cover service boundaries, data flow, storage, communication, scaling, consistency, fault tolerance, observability, deployment, and cost. Explain how your design would evolve under higher load and how you would validate important trade-offs.