Pros
Yandex is one of the top IT companies in Russia, engineering tasks are challenging, we compete monsters like Google and Uber, all that is really motivating. The company is expanding its office in Novosibirsk, so there is a sense of moving forward and growing all the time. Technologies depend on the team and product but generally are balancing between cutting edge and stability—we invent breakthrough things but found them on solid basement. The company cares for maintainability of solutions so there is a set of programming languages that are allowed. Salary and benefits are simply the best in the region. Engineers don't have any reason for leaving Yandex here, unless they decide to relocate somewhere.
Cons
Sometimes apples are not cut the way I like. Seriously, cannot find any downsides.