Pros
As far as startups go, this one's a hit! They hired the right people to make their vision a reality.
The people I work with are smart and friendly. Sure there's a lot of pressure, but it's pressure you apply to yourself after seeing how fast things have to move. It's a welcome challenge.
There are company BBQs and team building outings organized by the Office Manager that's pretty amazing.
Good work-life balance. No expectation to work OT or from home, but the problems we're solving, you'll probably want to put in a few hours a week at home anyway, because your individual contribution carries a great weight.
Cons
It's not always clear what priorities and timeslines are.