Facebook uses a mix of systems like MySQL for structured data and Cassandra or HBase for large-scale, distributed storage.
To understand "Facebook software," you have to look past the blue app on your phone. Behind that interface is one of the most sophisticated engineering stacks in the world, built to manage billions of users and petabytes of data in real-time. The Core Architecture: From PHP to Hack facebook software
Facebook began as a simple site written in , chosen by Mark Zuckerberg for its rapid development speed. However, as the site grew to millions of users, standard PHP couldn't keep up with the processing demand. Facebook uses a mix of systems like MySQL
