Nice article Gemain. Just one correction on Hopsworks. It uses MySQL Cluster (we call it NDB, not MySQL) and it is an in-memory database with the same read/write latency as Redis, but it is highly available (even across availability zones in the cloud, and can be asynchornously replicated across regions). The inventor of NDB, Mikael Ronström, also works with us as Head of Data at Logical Clocks.