The document discusses the technology and architecture behind the professional networking website XING. It describes how XING began with Perl and MySQL but has expanded to include additional programming languages, databases, and technologies. These include Ruby on Rails, Scala, Hadoop, Elastic Search, and more. The document outlines XING's development process, tools for version control, continuous integration, and deployment. It provides statistics on the size and traffic of XING's main Perl application and its infrastructure across multiple data centers.