Pros
After researching companies in the HR Tech space, this is the one that employees, customers (yes, I talked to a few before joining), and investors were most bullish about for four reasons. After working here for over a year, I have found them all to be true: (1) the core tech is truly remarkable, (2) the founders have "done it before" and operate with high integrity - they take feedback seriously and genuinely is trying to build a fantastic company, (3) the people at the company are deeply passionate about the mission, and (4) the growth is insane.
The pace is unbelievably fast - driven mostly by market demand. Great problem to have too much work if you can manage the stress that comes along with that growth, prioritize, and learn/build/teach process quickly.
Cons
All the cons that come with fast growth - need to hire more staff more quickly, build infrastructure as we are flying the rocketship, and improve communications across the company (a challenge I have experienced at 5 growth startups - moving fast seems to lend itself to communication challenges).