Great to be with and a-typical company, really worth discovering.
Pros
The work environment, relationships and incentives are sane and positive. People in your teams have a good skills and they are happy to be here and willing to help or to improve. The feeling that "we are in the same boat" dominates largely over any scope rivalry or counter productive incentives. The engineering culture is largely bottom-up: as individual contributor you can really push ideas or technologies through, you are encouraged (and reasonably well empowered) to take ownership of anything relevant. The culture is pretty international and taps into an interesting mix of "typical" US and French cultures, especially combining lightweight hierarchy with large autonomy in our missions.
Cons
Criteo is a bit "in-between" and this fuzzyness can be unsettling: not yet a giant of tech but not a startup any longer ; you are encouraged to challenges the rules but within established processes ; you are empowered also mean you can not expect precise scopes and objectives in some respect. Personally I like this in-between globally, but it can be exhausting at time and you have to be okay with this "meta-game".