Pros
There's incredible growth, and yet there's still a strong focus on work-life balance. No push to burn-out. There's a great mix of people and experience, which keeps it from that vapid monotonous "tech-bro" culture. It's nice working on an actual product that really does have a positive impact on people. Management is great: very approachable, communicative and collaborative. The executive team is friendly and transparent. It's very easy to work cross-functionally. I've seen lots of promotions from within and feel like there are good mentors and support for professional development. I've had lots of encouragement and support to try new things and pursue independent projects. There are lots of treats like free lunches, snacks, and social events, and their benefits packages have really grown up.
Cons
With all the growth comes some growing pains, as the company needs to figure out new processes and procedures. While I find that leads to exciting opportunities, it might be frustrating if you're looking for an established framework.