http://highscalability.com/stack-overflow-architecture
Saw this on yc and thought it was quite fascinating.
I love Stack Overflow and the biggest benefit I have noticed since their launch is that they have quickly overtaken Experts Exchange in Google results. I loath Experts Exchange and I don’t think I’m alone.
One thing that stands out is they use nearly a 100% Microsoft stack: Visual Studio, C#, SQL Server, IIS, ASP.Net MVC. The only part that appears to not be Microsoft is SVN. The author points out that it is actually quite difficult to find case studies which utilize the complete Microsoft stack. Which is surprising to me.
Also, on a technical note, I find it somewhat strange they actually copied a key part of the Wikipedia database schema, which they admit was a mistake.
They also mention the licensing costs and they can start to add up, but they get a discount from Microsoft BizSpark.
On a somewhat unrelated note, I actually got to meet and talk with the CTO of Wikipedia and attend a presentation he gave at the Orlando Java User Group, which was all about scaling. I wish they would have posted the slides and transcript because it was absolutely awesome!