How do I approach System Design interview questions?

System Design questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master system design interviews.

What difficulty level is this interview question?

This is a hard difficulty System Design question, commonly asked during Technical Screen rounds at Google.

What role is this question designed for?

This question is commonly asked for Software Engineer candidates at Google during technical interviews.

Design deduplicated file storage on filesystem

Quick Overview

This question evaluates system design and storage engineering competencies, including multi-tenant isolation, authentication and authorization models, content-addressable storage and deduplication, reference counting and garbage collection, concurrency control, API surface design, and scaling across nodes using only filesystem primitives.

System Design Task: Filesystem-Only, Multi-tenant, Deduplicated File Storage

You are asked to design a multi-tenant file storage service with the following constraints and requirements:

Only OS filesystem APIs are allowed (e.g., directories/files, permissions, hard links/symlinks, atomic rename, file locks, fsync). No databases or external KV stores.
Users belong to tenants; tenants must be isolated from each other.
Identical files must be deduplicated.
Define and justify the following:
1. Authentication and authorization (who can upload, read, delete).
2. Object naming and tenant namespace layout.
3. External APIs (upload, get, delete; optionally list, head, copy).
4. Content-addressed storage and deduplication strategy.
5. Reference counting and garbage collection.
6. Consistency and concurrency semantics under concurrent uploads/updates/deletes.
7. Scaling across multiple storage nodes (sharding, replication assumptions, routing).

Assume a POSIX-like environment supporting atomic rename, hard links, advisory file locks, and SHA-256 hashing.

Quick Overview

System Design Task: Filesystem-Only, Multi-tenant, Deduplicated File Storage

You are asked to design a multi-tenant file storage service with the following constraints and requirements:

Only OS filesystem APIs are allowed (e.g., directories/files, permissions, hard links/symlinks, atomic rename, file locks, fsync). No databases or external KV stores.

Users belong to tenants; tenants must be isolated from each other.

Identical files must be deduplicated.

Define and justify the following:

Authentication and authorization (who can upload, read, delete).
Object naming and tenant namespace layout.
External APIs (upload, get, delete; optionally list, head, copy).
Content-addressed storage and deduplication strategy.
Reference counting and garbage collection.
Consistency and concurrency semantics under concurrent uploads/updates/deletes.
Scaling across multiple storage nodes (sharding, replication assumptions, routing).

Assume a POSIX-like environment supporting atomic rename, hard links, advisory file locks, and SHA-256 hashing.

Design deduplicated file storage on filesystem

Quick Overview

System Design Task: Filesystem-Only, Multi-tenant, Deduplicated File Storage

Solution

Comments (0)

Design deduplicated file storage on filesystem

Quick Overview

System Design Task: Filesystem-Only, Multi-tenant, Deduplicated File Storage

Solution

Comments (0)