Pros
I've worked at Mediamath for over a year. In Engineering it's a lot less top-down than I've seen at most other organizations both in terms of managerial structure or attitude as well as technology stack. There's a healthy lack of self-satisfaction in the technological status quo, and instead there seems to be a constant striving in doing things cheaper, faster, and better. This does not mean to say the environment is high-pressure because, on the contrary, I've found it to be one of the most relaxed places I've worked. We have unlimited PTO and it's for real, meaning if you are capable of delivering good results then no one questions when or how you go about it. Other pros: People and culture are friendly and diverse; good benefits and free snacks; the view is awesome.
Cons
Onboarding could be better; wiki organization is pretty bad.