The front end does, that was built by Development Seed. The problems have seemed to come from other contractors, such as CGI Federal, though I'm loathe to trust anything I've read in the news about this clusterfuck so far. The reporting has been so bad it rivals Healthcare.gov itself in its awfulness.
The craziest part has been the hysteria about the healthcare.gov repository going down. It never contained any files that were useful to anyone - it was just the blog / landing page. It's like Microsoft promising to open-source their operating system and all you get is the software that generates the help files.