Built to scale

How do you build a scalable system? How do you know if you have one? What does "scalable" even mean? Your database vendor says their product is scalable, and so is your application server. Your hosting provider also has infinite scalability, not to mention your web application framework, and of course the bill for the consultants you've hired to implement it all.

It doesn't need to be that hard. In the end it's about applying a few very simple rules, and using some basic patterns. Building to scale is not about the programming language, but using a language that gets out of the way, like Ruby, also makes it so much easier.