How and Where does Github stores all the millions of repositories and billion of files?

Does it uses something like AWS S3 or it's own dedicated storage servers?Are there open source libraries/file systems to manage such a huge amount of files efficiently?

Atul Sharma's photo

Here's the complete list of technologies backing Github :

Arun Kirubarajan's photo

In addition to tech stack, another important thing to remember with Github (and any other Git hosting service like GitLab) is that they don't necessarily have to store each individual file for each commit.

Linus Torvald's amazing creation of Git handles the storage of changes remarkably well, which contributes to the storage of Github's files.