That's pretty cool! Figured about Python (saw gunicorn in HTTP headers).
What blew me away, is the fact that you're using a custom framework for the user on-boarding complex/heavily-ajaxified UX... I'd be willing to get updated about how does that scale up!
To be honest, the onboarding experience is pretty silo'd in terms of scripting, although we're thinking about using the same functionality (guided walkthrough) for other parts of the experience, so I may refactor it for reuse elsewhere :)
