Design a Durable Concurrent Event Writer
Company: Databricks
Role: Software Engineer
Category: System Design
Difficulty: hard
Interview Round: Onsite
Overview: Design a thread-safe local event writer shared by thousands of producers appending opaque records to one file. Define ordering and return guarantees while addressing interleaving, bounded backpressure, batching, disk errors, torn writes, graceful shutdown, crash recovery, and operational metrics.