Google Web Server

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Google Web Server (GWS) is Google’s private web server software. It is proprietary and used only inside Google to run its websites and services. GWS is written in C++ and runs on a heavily modified Debian Linux system.

The GWS team is considered one of the most guarded parts of Google’s infrastructure. In 2008 the team was led by Bharat Mediratta.

GWS has had a noticeable share of the web: in 2010 it was reported to power about 13% of all websites worldwide. In May 2015 it ranked as the fourth most popular web server on the internet, after Apache, Nginx, and Microsoft IIS, and was estimated to power about 7.95% of active websites.

If you visit Google pages, you’ll often see the gws string in the HTTP header, which identifies the Google Web Server software in use.

Details about GWS are not widely published. A 2011 Google blog post from the Chicago office described it this way: the GWS team builds and maintains Google’s internal web-serving system that powers Google Search and other properties. GWS is involved in most user-visible changes to google.com, and Google seeks engineers with strong systems skills and experience working with large C++ codebases.