Design a secure document vault
Company: Harvey
Role: Backend Engineer
Category: System Design
Difficulty: medium
Interview Round: Onsite
Design a secure document vault product similar to a cloud repository for sensitive files. The system should allow authenticated users to upload, store, and retrieve documents, while enforcing strong authorization rules.
Expected follow-up topics include:
- How would you scale the system as file count and traffic grow?
- How would you design access control and permission checks?
- How would you handle very large file uploads?
- If files are uploaded to object storage such as S3 in multiple chunks, how can the system verify that each uploaded chunk actually belongs to the intended file and authorized user, rather than arbitrary data uploaded by a malicious client?
Discuss APIs, metadata storage, authentication and authorization, upload workflows, integrity verification, and operational concerns.
Overview: This question evaluates a candidate's competencies in secure backend system design, covering authentication and authorization, metadata and object storage architectures, integrity verification for chunked uploads, scalability, and operational reliability.