Ten years ago a site like Ravelry would have been a multi-million dollar operation. Today Casey is the sole engineer for Ravelry and to run it takes only a few people. He was able to code it in 4 months working nights and weekends. Take a look down below of all the technologies used to make Ravelry and you'll see how it is constructed almost completely from free of the shelf software that Casey has stitched together into a complete system. There's an amazing amount of leverage in today's ecosystem when you combine all the quality tools, languages, storage, bandwidth and hosting options.
Really interesting and quick read (link to a great interview at the top of the article as well) about building and scaling what started out as a small site (don't they all?). Excellent details about the technologies used and why, and nice lessons learned. "Keep it fun" is one I continually have to remind myself.