Interesting that the bulk of their web interface was written in CoffeeScript at the time of the answer even though they weren't using Rails. I've just never seen a well-known product using CoffeeScript without Rails.

I do wonder if that remains to be the case or if they've moved their web interface to something else. They've released a number of new products the past year, and I'm sure at least one isn't CoffeeScript given the content of the post.

I believe Stripe is Sinatra with a custom rolled ORM. Seem to remember one of the founders posting that...maybe even here on HN.