Design a Cache with Hit Counts
Company: Databricks
Role: Software Engineer
Category: Software Engineering Fundamentals
Difficulty: hard
Interview Round: Onsite
Design a key-value cache that supports get(key), put(key, value), and delete(key). In addition, the cache must track how many successful reads each key receives. Explain the API, internal data structures, eviction policy, concurrency model, time complexity, and how you would extend the design if the cache needed to run across multiple machines.
Quick Answer: This question evaluates a candidate's competence in system design, data structures, concurrency, and observability by requiring a key-value cache that tracks per-key read counts while supporting get, put, and delete operations.