Pros
The people and culture. The leadership. The ability to work on so many things without ever feeling pushed to give up your personal life. I've been here for over two years, and an eventual con was that the team was so new and young, we were all figuring it out together. At the time this was a huge pro, and felt like a life-time crammed into a single year, but over time this freedom ran its course. Now, with a huge crop of experienced leaders joining the crew, there has been mentorship aplenty. It's been really incredible and I feel really lucky for getting a front row seat in so many arenas where I otherwise may have found myself 3 or 4 org levels away from the action. The company also is responsible. Kind. Fun. Strategic. Tim and Jordan (the two founders) really really CARE about the people and employees. They do a good job walking the balance between caring for the larger group and also doing what they can for the individuals.
Cons
The cons become fewer and fewer as time moves on. Kicking off hyper-growth and watching every system break faster than you can fix it was (is) exhausting. Everyone is doing a million things at once, so sometimes communication can break down, but everyone is been pretty awesome about being forward-looking and strengthening the team. You may have to walk 5-8 minutes because you have to park in the neighborhood (oh no! LA weather!) or walk to the farthest bathroom (we have five bathrooms and I've literally never seen all five occupied at once), but honestly if those are the things that turn you off, working at a start-up is not a match for you.