It looks like a weekend project but isn't. Scaling it up took Twitter a long time. Showing your feed is a very expensive operation (there are users with a large

It looks like a weekend project but isn't. Scaling it up took Twitter a long time. Showing your feed is a very expensive operation (there are users with a large number of followers and users who follow many others) and syndication and clients amplify the number of operations. Source: I was one of the developers of Jaiku, which had a very similar model.