21. Github


Design a file hosting and version control service like Github

Functional Requirements
  • Users should be able to push versions of their files to a central store that houses all of their organizations files
  • Users should be able to pull the latest changes
  • If you try to push a file that has already been changed, you receive an error that you have to pull first
  • Users are able to access all files in their organization
Nonfunctional Requirements
  • Fault tolerance required
  • P99 for uploading a file can be no worse than 4 seconds
  • Only users in an organization can access the files
  • 2 new files are uploaded every push
  • 3 files are changed every push
  • 1 out of every 5 pushed is blocked by a merge conflict
  • All files are text and on average 2kb
Estimated Usage
  • 85 million users
  • 400,000 organizations

Seen this question in a real interview before?

Not all editor features are supported on mobile