Ask HN: Are there successfull, ajax-heavy SaaS Apps by small teams?

I use a number of SaaS platforms daily - none of them very ajax heavy (no single page app type things) other then gmail -- which certainly is not maintained by a 'small' team.

My experience has always been that ajax-heavy apps are more difficult to maintain, and take more developer hour to build and add features to. Maybe I'm doing it wrong.

Does anyone have any examples of successful, heavily ajax-based SaaS apps that are built and maintained by small teams?