I would consider myself to be fairly agnostic when it comes to languages (although Python happens to be the language I work most with, which has a lot to do with what my coworkers prefer). What I can say is, that quite often, those large distributed system solutions has high constant offsets / penalties if you aren't building the BIG solution. so everything, starting from functional testing to those small tasks that happen more often than one would like take ages. I wouldn't be surprised if a python stream processing framework could provide a good developer-happiness -- efficiency ratio, just by being responsive.