When it comes to providing PaaS hosting solutions for Ruby development, Heroku and Engine Yard are the de facto leaders. And they both utilize Amazon’s EC2 as a hardware base. However, they also take different paths to get there – Heroku offers isolated slices of EC2 instances, called dynos, that offer very limited access to the underlying infrastructure. Engine Yard offers a curious PaaS-IaaS hybrid; you have much more access to the underlying VM, you get a full EC2 VM to work with, but at the same time you also get an ready-made environment for application development. Let’s peek under the hoods of both solutions.