The Inner Workings of a Realtime Search Engine

So they are basically combining google + digg, indexing pages while taking account of user feedback through a recommendation system. Actually... I don't see what the big deal about "realtime search" is and the whole article sounds a little like PR material rather than a technical explanation of the inner workings of their search algorithm.

Also keep in mind that this is the same company that was me.dium, the company which got 15 million dollars of funding with like... (20k ? ) users, somewhat a poster-child of the web 2.0 bubble. I guess their original idea didn't take off and they started this instead.

I would be more interested in their search infra, specifically scaling that "highly optimized in-memory index".

I'm guessing it's similar to LinkedIn's Zoie (http://code.google.com/p/zoie/).