I'm also very interested in the details of your event streaming. Are you using Node.js streams at all? I am a huge fan of Node streams but see few examples of them used in large-scale production, especially when combined with other architectures (as in your Java Storm example).
We are currently not using nodejs streams. The nodejs components are the event dispatchers placing the events in a queue, they do not include much even processing. Most of the event processing is done in Apache Storm. We have also contributed the Storm-Nodejs integration, but the nodejs Storm components are not using streams either. I have tried using streams to compress the information between the Java parent process in Storm, and the nodejs child process, but compression wasn't a good tradeoff, so even that little bit didn't get into production.