Nice place, nice people, good engineering culture
Pros
1) Great culture, great engineering challenges 2) Company is loyal for its employees and has good understanding of the employees market. It 2014 crisis in Russia they decided to compensate the falling ruble course - not too much companies done the same thing in that time. 3) You can work with best engineers from IBM, Cisco, Intel, Red Hat and all other companies who contribute to OpenStack.
Cons
Founders can make very weird decisions. In 2017-2018 company lost a lot of very great engineers and brilliant minds (I was left too, but I'm more than average) by making very controversial business decisions. It looks like Mr. Fridman can make only outsourcing company. It was a dark times when Adrian Ionel left the company. It looks like he has a very good product vision. Also there were some hirings of VP-level people in USA from top-level companies and it looks like most part of them didn't done their job well. The left company silently.