I wonder why they chose Apache instead of something like NGINX instead which is far superior and scales a whole lot harder than Apache can? I've seen Apache in the right hands scale well, but why make things harder for yourself than they need to be when you can use NGINX which is lighter and consumes less CPU and memory?

Cool stack though. Seems like MongoDB has emerged as the clear winner in the commercial NoSQL arms race. I do like it and with every release it's getting better and more feature-packed.