It seems LedgerStore is not open source [1], and finding any info on it requires following a trail of backlinked Uber blog posts. Here's one with the most info on LedgerStore that I can find, from 2021:
Yeah. This looks like some internal solution.
In general Uber seems to be high on "not invented here" scale - they like to conclude no existing Open Source solutions are good enough for them and they need to build their own... this is different from Facebook approach for example which chose to made MySQL better by adding MyRocks/RocksDB to it and keep them Open Source.
It's a weird world where Facebook/Meta is becoming a small bastion of hope. Llama 2/3 being an example of bucking the trend of going closed source for LLM models.
Granted it's not quite in the same calibre as OpenAI/Claude, and the real test is when it is and they still release it.
https://www.uber.com/en-US/blog/dynamodb-to-docstore-migrati...
[1]:https://github.com/uber