A lot of their products are very solid. We have, at home, Yandex Music which is way cheaper than Spotify (and is quite different) and Alice, which is their Alexa equivalent. If you speak Russian, its quite good :)
In general, while I was visiting Russia last year and the year before, Yandex Taxi (like Uber) impressed me quite a lot, too.
Russian engineering is next level. Just look at Telegram. The thing works flawlessly with billions of messages everyday and Slack struggles with some basic chat.