Pros
I've been working at Valkyrie for 6 months now and I absolutely love it. The leadership team is supportive and transparent. The company is quickly growing, so every day is a bit different. The team members are made up of diverse backgrounds and since our team is relatively small, everyone has become friends. It's a good mix of startup + consulting culture. As a small company, team members have the opportunity to work across departments and learn from the scientists and strategists. The leadership makes it apparent that they're invested in everyone's professional development (they've already paid for me to go to one offsite training) and is open to feedback. I recommend this company for anyone who's interested in data science and machine learning, is a self-starter, can adapt to a fast-paced environment and think critically.
Cons
Valkyrie works in a highly technical field, so if you don't know a lot about data science, expect a learning curve (though the science team will help you as much as they can).