System requirements
Functional:
User authentication and authorization
File upload and download
Synchronize across multiple devices
File sharing
Version control and history
Folder creation
Search
Offline Access
Storage quota management
Notifications
Non-Functional:
Scalability.
Horizontal scaling for file storage.
Sharding to distribute data across multiple databases
Microservices architecture
Asynchronous processing for file uploads
Available
multi region support
Robust monitoring and alerting
retry mechanism with exponential backoff
Durability
Replication
Data integrity checks
Performance
Chucked file for large file transfers
Asynchronous IO operations
Capacity estimation
Estimate the scale of the system you are going to design...
API design
Authentication POST /api/v1/auth/register POST /api/v1/auth/login POST /api/v1/auth/logout POST /api/v1/auth/refresh-token
- File Operations POST /api/v1/files/upload GET /api/v1/files/{fileId} PUT /api/v1/files/{fileId} DELETE /api/v1/files/{fileId} GET /api/v1/files/{fileId}/versions POST /api/v1/files/{fileId}/restore
- Folder Operations POST /api/v1/folders GET /api/v1/folders/{folderId} PUT /api/v1/folders/{folderId} DELETE /api/v1/folders/{folderId}
- Sharing POST /api/v1/files/{fileId}/share DELETE /api/v1/files/{fileId}/share/{shareId}
- Search GET /api/v1/search?q={query}
- User GET /api/v1/user/quota GET /api/v1/user/recent-activity
- Sync GET /api/v1/sync/changes?since={timestamp} POST /api/v1/sync/upload-batch ```
Authentication: Use OAuth 2.0 with JWT tokens for authentication. Include the token in the Authorization header for all authenticated requests.
Request/Response Format: Use JSON for request and response bodies. Use standard HTTP status codes for responses.
Database design
User
{ id: UUID, email: String, passwordHash: String, name: String, createdAt: Timestamp, updatedAt: Timestamp, storageUsed: Long, storageQuota: Long }
File
{ id: UUID, ownerId: UUID, name: String, type: String, size: Long, path: String, parentFolderId: UUID, createdAt: Timestamp, updatedAt: Timestamp, lastModifiedBy: UUID, isDeleted: Boolean, deletedAt: Timestamp }
FileVersion
{ id: UUID, fileId: UUID, versionNumber: Integer, size: Long, createdAt: Timestamp, createdBy: UUID }
Folder
{ id: UUID, ownerId: UUID, name: String, parentFolderId: UUID, path: String, createdAt: Timestamp, updatedAt: Timestamp }
Share
{ id: UUID, fileId: UUID, sharedBy: UUID, sharedWith: UUID, permissions: String, createdAt: Timestamp, expiresAt: Timestamp }
Storage: Use a combination of SQL and NoSQL databases. - SQL (e.g., PostgreSQL): For user data, file metadata, and relationships - NoSQL (e.g., Cassandra): For file versions and sync logs - Object Storage (e.g., Amazon S3): For actual file content
Data Transportation: Use a message queue (e.g., Apache Kafka) for asynchronous operations like file uploads, downloads, and sync events.
Encryption: Use AES-256 for encrypting files at rest and TLS 1.3 for data in transit.
High-level design
You should identify enough components that are needed to solve the actual problem from end to end. Also remember to draw a block diagram using the diagramming tool to augment your design. If you are unfamiliar with the tool, you can simply describe your design to the chat bot and ask it to generate a starter diagram for you to modify...
Request flows
Explain how the request flows from end to end in your high level design. Also you could draw a sequence diagram using the diagramming tool to enhance your explanation...
Detailed component design
Dig deeper into 2-3 components and explain in detail how they work. For example, how well does each component scale? Any relevant algorithm or data structure you like to use for a component? Also you could draw a diagram using the diagramming tool to enhance your design...
Trade offs/Tech choices
Explain any trade offs you have made and why you made certain tech choices...
Failure scenarios/bottlenecks
Try to discuss as many failure scenarios/bottlenecks as possible.
Future improvements
What are some future improvements you would make? How would you mitigate the failure scenario(s) you described above?