Your question is Scaling Bottlenecks. 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 handle scaling bottlenecks in a system you designed?
Explain how you would identify the bottleneck, distinguish capacity problems from architectural limitations, prioritize corrective actions, and manage delivery risk. Cover measurement, trade-offs, rollout strategy, and how you would validate that the system remains reliable as demand increases.