Facebook employees are an elite group of coders, engineers and entrepreneurs who have all it takes to manage the 400+ million user base Facebook has developed over years. The Facebook team is extremely small and the ratio of a Facebook engineer to Facebook users is more than one million. This is possibly the largest ratio amongst all tech giants.
Facebook is now a part of 2010 TopCoder(R) Open as a sponsor. It also has plans of taking in winners as interns and full time employees. Facebook says,
Help develop the second most-trafficked site and one of the largest MySQL installations in the world.
Facebook uses PHP, C++, Python, Java and Erlang besides other languages.
Every technology has some form of a limit. Tech companies like Facebook hack these technologies to scale them according to their needs and go beyond that limit. Facebook uses Cassandra, Hive, Scribe, and Thrift open source projects and is active in developing them as well.
Facebook boasts more by saying,
At Facebook, we move fast. Our rapid development cycle is supported by tools that always keep us operating ahead of the curve. Our engineers are able to write code and have it running live on the site that same night – see the impact you’re making in real-time.
Learn more at the http://www.topcoder.com/tco10 page.