Pardon me then, I had taken it that you built large systems using Heroku as a platform not actually working for Heroku. You probably do have some incredible problems to solve. I was asking the question because I find the whole platform as a service category to be a very interesting realm of where technology has gone. As such, I've been curious about folks who are using Heroku for some really big things and why they chose to do so over using their own servers. Particularly from the perspective of administrators in charge of keeping said systems up and running.