Well perhaps its a matter of staring at something so long it becomes simple. But I really don't think what I am suggesting is that hard. The main thing that requires some thought is shard splitting. That is not a big piece of code, but it does admittedly take some thought to get right. Aside from that everything else is provided out of the box by someone else like amazon web services or terracotta. I am not sure how I could have been more precise without source code.

It is certainly reasonable to suggest that Twitter is good enough as it is because people still use it, though the grumbling in the market suggests that that may not be something they can bank on forever.