For the past 6 months we at Wix have been working very hard to switch from a single platform that is based on creating Flash web sites to a multi-platform that can handle any type of site.
During that time my wonderful server group basically had to re-write Wix’s entire back-end infra-structure to be able to support multiple application types which currently consists of HTML5, Flash, Mobile, Facebook pages and Blog.
Until the HTML5 switch the Flash site was the only entity that Wix’s systems knew how to work with, the HTML5 was a big challenge for the back-end team since now two applications can occupy the base url. Let me explain: www.wix.com/aviran/mysite can now point to either flash or HTML5 site. Now the server needs to decide based on the url which site to render, which basically dispatches to a different application renderer. Since the old system was not designed to support multiple application types we had to redesign our entire back-end system which affected all the segments.
I invite you to check out the revolutionary best HTML5 editor on the web.
Full Disclosure: Aviran Mordo works as the server group manager at Wix.