Pros
Incredible work atmosphere and work/life balance. The team dynamic at this company is the best I have ever experienced. You get the feeling that everyone is working together to solve whatever problem the team is faced with. The core dev team of front end, back end, and QA are in constant communication, giving a real feeling that you're involved in every part of what is going in.
The mentorship on the dev team is also amazing. The senior engineers on the team are highly competent and always willing to explain how elements of the system work (though sometimes in too much detail). The team here is constantly improving and investing in professional development.
Cons
Sometimes the dev team has difficulty distributing the work between engineers. I think this is a growing pain that comes with being a startup. If something is high enough priority, there can sometimes be members of the team who are extremely busy, while others do very little.
Meetings tend to last longer than they should.