Yandex used (maybe still using) SVN monorepo named Arcadia for most of the source code. As it became too big, they developed an in-house VCS called Arc and were switching to it; there is more context in a presentation about Arc (2020), transcript/recording in Russian[1]
I could assume that this is the leak of Arcadia, and each archive roughly contains one top-level folder.
I could assume that this is the leak of Arcadia, and each archive roughly contains one top-level folder.
[1]: https://habr.com/en/company/yandex/blog/482926/