Disclaimer: I worked at Yandex in 2006-2007.

Yandex is a very BIG company in terms of users, requests, data stored etc. It's surely bigger than Twitter, I believe it is bigger than Netflix. It is also algorithms company (like "not content company") So, when Yandex doing something, is mostly doing it because all other options were failed on their load.

Yandex also has a very extensive expertise in C/C++. There is a ClickHouse, there is a CatBoost. I would trust them in their domain.