I wonder if this would have built on Apache Pulsar (https://pulsar.apache.org) if it had been in open source and on the Segment team's radar at the time they started on Centrifuge. I work with one of the architects of Pulsar, and his first thought on seeing the blog was that Segment's scenario had a lot of similarities to what he and the team and Yahoo set out to do when they first built Pulsar there several years ago.