If I had to guess, they are probably using XTDB, which is bitemporal, i.e. every entity has an associated "transaction time" and "validity time". You can use the validity time to deal with situations like "Company reported X assets and Y liabilities in their 2020 balance sheet, and in 2022 it was discovered there was some 2020 assets unaccounted for", and in addition to this, answer questions like "How much assets did Company believe it had in 2020 given the facts we know in 2020? How about given the facts we know in 2022?"
I am not sure how useful this is for versioning data though. It seems like an orthogonal problem to me.
I am not sure how useful this is for versioning data though. It seems like an orthogonal problem to me.