Your question is Design an Efficient Cache. 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 cache mechanism to store and retrieve data efficiently.
Clarify the scope of the cache, including read/write patterns, freshness requirements, eviction policy, and consistency guarantees. Then propose how you would size, shard, invalidate, monitor, and recover the cache under peak traffic and partial failures.