This is usually what people would do when using NoSQL database to reduce latency by caching elements with an in-memory database.

Basically they are mixing up Redis with RocksDB , which is what devs usually do to get even higher throughput by storing IDs in Redis to save a call to RocksDB.

Now what bother me is the look of repository , it looks completely rushed out.

No logo , unclear description of the tech...

Hence , as other mentioned it's just "an engine" , it doesn't actually contain the network layer, the clustering mechanism etc...

I guess it's probably the tech that is powering their flagship engine : "CosmosDB".