[zd4akaq85a]

An Uber engineer at a conference said that none of the open-source NoSQL systems could handle their load, and they they had to heavily hack one of them (which I think was Cassandra but the memory is vague) to get the last bit of performance out of it while they were building Schemaless.

[web007]

They seem to be running Cassandra still, at least as of last month - "Running Cassandra on Apache Mesos Across Multiple Datacenters at Uber" https://www.youtube.com/watch?v=U2jFLx8NNro