Pros
The people - in addition to being friendly and really easy to get along with, everyone is extremely smart, hard-working, and focused on meeting goals and getting things done. You will learn a lot from everyone around you. Super collaborative environment, lots of problem solving, productive discussions and continuous improvement. The leadership is inspiring and experienced with a great track record for building successful companies. They do not hesitate to communicate that the goal here is to WIN - this is not a 'chill startup' gig for someone looking for a 'cool job'.. it's an opportunity to be a part of something and the leadership is putting faith and trust in the employees to get it done.
Cons
While I don't personally find it to be a con, it is a very fast-paced environment and given the nature of any startup, it can mean priorities/processes/projects are constantly changing. Not a lot of hand-holding, you will be expected to learn quickly and adapt. There is no down time and the hours can be long but if you are up for the challenge, it's worth it. The potential for the company is tremendous!