Pros
AdTech is an area that is just starting to take off and it's spectacular to be on the ground floor of a company that is really willing to listen to it's employees to ensure they have what they need to be successful. The benefits are top notch and there is a very laid back, friendly environment. I also feel like I have the support from my team (HR) to really grow into my career. Best piece of advice- make sure to surround yourself with smart people and you can only grow from there! I feel like I've definitely done this at MediaMath.
Cons
Sometimes, things to feel a bit unorganized; however, it seems like things are slowly getting back on track as MediaMath listens to it's employees. In a company that grew as fast as MediaMath did, these things tend to happen. Lack of space is an issue (when is it not!); however, I can see the wheels turning to fix issue so hopefully it will happen soon.