Table of content:

• Functional Requirements
• Non Functional Requirements
• Capacity Estimation
• High Level System Design

File Hosting Service like Dropbox enables users to store their data on cloud. These servers are maintained by cloud storage providers and made available to users over a network.

Functional Requirements

1. User should able to upload/download files
2. System should sync files across all devices

Non-Functional Requirements

1. System should highly reliable/scalable
2. System should be highly available with eventual consistency

Capacity Estimation

Throughput

• Read and Write heavy System
• DAU : 1M users and 10 files upload/day
• 100 uploads/sec

Storage

• 100MB X10M -> 1000 TB/day - 1 Peta Byte/day

High Level System Design

• Internal Metadata: Will keep track of all the files, chunks, their versions and their location in the file system
• Chunker split the files smaller pieces called chunks. it will also be responsible for reconstructing a file from its chunks.
• Watcher monitor the local workspace folders and notify the indexer of any file changes
• Indexer communicate with the remote synchronization service and internal metadata DB.