Context is important. A no-Photoshop approach makes sense for Quora since their product is text-heavy. For a product that requires, say, rich data visualizations like Google Analytics, some design ideas need to be mocked in a graphics package (Googlers often use Fireworks instead of Photoshop) first, then prototyped in code.<p>Context is also important in terms of what stage of the development process the designer is at. If a product design is already well defined (e.g. "top nav is global, 2 columns in the core content space, right column is contextual nav, left column is the content stream, here's the style guide ..."), then going directly to code makes sense. As Joel suggests, going directly to code is great for day to day new feature iterations.<p>But if your product is completely undefined, Photoshop or Fireworks can be excellent tools for mocking up design variations and sets of use cases or states within those variations.<p>Hats-off to Quora for going straight to code when it comes to design. It works for them but it's not going to work for everyone in every case.