Honest question, why would Rapgenuis still be on Heroku if the y needed 100 dynos? Why not go directly to AWS at that scale? The cost savings would be pretty significant. Am I missing something?
Ops guys cost a lot more than just using Heroku, not to mention the cost of simply having the responsibility of servers (even if they are virtual). Never underestimate the value of just not having to think about something, especially when you're small group of people.
Before you undertake the more significant time and cost of migrating platforms, you see what you can wring out of what you've got. It is possible that after improving their performance enough on Heroku (or hell, even without improving it), they can not justify the up-front money and resources to migrate platforms.
Or, for all we know, they could already be in the process of migrating away from Heroku, but that doesn't happen overnight and doesn't help their performance in the meantime.
