A meetup consisting of casual evening talks and demos on the challenges and solutions of building and maintaining Wikipedia and associated sites (Wikimedia Commons, Wiktionary, Wikiquotes, …) at the scale of a top five Internet site with over half a billion monthly uniques. This will be followed by Q&A and other informal lively discussion before and after. This consists of a range of topics such as the MediaWiki software (one of the largest open source web projects), website architecture and infrastructure, mobile devices, product design, internationalization and localization, fundraising engineering, new features engineering, and operational and testing infrastructure. The Wikimedia Foundation is headquartered in San Francisco, so it likely that the majority of presentations will be done there. Though it is likely that the presentations themselves will be streamed over the web. Join this if you are interested in web development (especially, but not exclusively, in PHP and JS), mobile web and app development, devops, mobile development, product design & development as well as open source outreach and development.