Your question is Scalable Leaderboards for Concurrent Players. 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 design a service to handle leaderboards at Zynga for millions of concurrent players? Explain how scores are submitted, validated, ranked, stored, and served during normal operation and traffic spikes. Address consistency, partitioning, latency, cheating, pagination, regional or global rankings, and operational failure recovery. Clarify missing scale assumptions before sizing the system. Discuss whether machine learning is necessary, and where an ML component could safely assist without becoming the source of truth.