We built Bitsmachine with Ruby, Rails, GitHub, and hosted on Heroku. Since I did’t program in Ruby/Rails at the time (I do now, moreso), this kept me focused on front-end design and engineering.
I researched the product among a portion of the design community I could easily reach and ran some small studies to test the potential viability of the product.
I chose Haml and Compass/Sass for HTML templates and CSS. I built up a small library of Sass mixins and structured the site CSS so it could be easily themed.
Sass allowed me to separate different areas of the site (public, application, and portfolio) into their own CSS files, while maintaining consistency through the use of a common library (buttons, forms, typography, layout, etc.). In fact, I recommend breaking up your Sass files wherever possible. Smaller, more organized files are much easier to maintain.
We focused on making Bitsmachine as beautiful and easy to use as possible. We chose a simple, straightforward portfolio structure that would be easy for viewers to explore. That meant choosing sensible defaults for most design elements, and making sure that what customization options we did include offered maximum impact.