Involving design in the process early and often is how we maintain a great balance of friendly UI and powerful tools to maintain your system. One of our key values is: "Strive for simple and elegant solutions" and we keep that in mind with every iteration on our product.
In terms of technologies, it depends on which part of the product. digitalocean.com is built using Middleman, while some of our other pages such as the Community and Cloud site use Ruby and/or Ember.