Design a Thread-Safe Buffered Writer with a Background Flush Thread
Company: Databricks
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Onsite
Quick Answer: This question assesses a candidate's ability to design a concurrent, thread-safe component that decouples fast in-memory writes from slower disk I/O using a dedicated background thread. It probes practical understanding of concurrency control, buffering and batching strategies, backpressure, and durability guarantees in a systems design context. It is commonly used to test applied, real-world concurrent-systems reasoning rather than pure algorithmic recall.