Well since you use clojure, you probably know that to have small codebase, people often pick clojure. Going from point A to point Z quickly is rarely a goal for startups, going through A.. B... C... quickly, is the goal. I am still looking through all this, but a thought of having to bet on some java api + hope and pray it will jump over all unknown hoops, hm.

Comparisons to twitter are unfair, twitter is not really technical gem or is it? It's pretty impressive to build it with 3 ppl in 3 months, but hmm also seems feasible using other tech, given all blueprints are out there.