Cheaper licensing was attained through Microsoft's BizSpark program.9 million active programmers in the world and 30% have used Stack Overflow.3 million unique visitors a month (Facebook reaches 77 million unique visitors a month).Let's see how they did it and you be the judge. He wonders if these other sites have good programmers. Joel boasts that for 1/10 the hardware they have performance comparable to similarly size sites. Maybe someday we'll have the best of both worlds, but for now there's a big painful choice to be made and that choice decides your fate. In this era of multi-core, large RAM machines and advances in parallel programming techniques, scale up is still a viable strategy and shouldn't be tossed aside just because it's not cool anymore. When thinking about your design options keep Stack Overflow in mind. But Stack Overflow is not Google and neither are most sites. If you need to Google scale then you really have no choice but to go the NoSQL direction. The publicity these days is all going scale out using NoSQL databases. What is key about the Stack Overflow story for me is the strong case they make for scale up as a viable solution for a certain potentially large class of problems. It's the conscious awareness of the mechanisms that creates such a satisfying synergy. Use design to engineer in the behaviours you want to encourage and minimize the responses you want to discourage. I also appreciate their no-apologies anthropologically based design philosophy. I fell in deep like with Stack Overflow for purely selfish reasons, it helped me solve a few difficult problems that were jabbing my eyes out with pain. Joel estimates 1/3 of all the programmers in the world have used the site so they must be serving up something good. In that sense Stack Overflow is like a celebrity owned restaurant, only it should be around for a while. The site was created by top programmer and blog stars Jeff Atwood and Joel Spolsky.
Stack Overflow is a much loved programmer question and answer site written by two guys nobody has ever heard of before.
Update: Startup – ASP.NET MVC, Cloud Scale & Deployment shows an interesting alternative approach for a Windows stack using ServerPath/GoGrid for a dedicated database machine, elastic VMs for the front end, and a free load balancer.
Update 2: Stack Overflow Architecture Update - Now At 95 Million Page Views A Month