Design a Hierarchical File System
Company: Databricks
Role: Software Engineer
Category: System Design
Difficulty: hard
Interview Round: Onsite
Design a hierarchical file system service from scratch without relying on an existing blob store. The system should support creating files and directories, reading and writing file contents, listing a directory, and deleting a directory recursively. Focus especially on how directory listing and directory deletion should work, including metadata layout, consistency, locking, storage of file data, and recovery from failures.
Quick Answer: This question evaluates a candidate's proficiency in system design for storage services, covering hierarchical namespace modeling, metadata layout, directory listing and deletion semantics, consistency and locking strategies, data storage organization, and recovery from failures.