Pros
Mapbox is one of those companies that is truly disrupting a space that was ripe for innovation. I had work experience in this mapping in location space prior to working for the company, and once I learned about what Mapbox was doing, I told myself I *had* to work here. I have learned so much and have not regretted a second of my time here. The calibre of the people, their intelligence, and also the kindness of people I have worked with has been really impressive. Employees are largely driven by a genuine desire to change the world, the help customers, and in the community area - to help people in need, to support first responders, and to enable new ways of solving human and technical problems.
Cons
Like any successful, high growth start-up, things move fast. There is also constant change. Just like in life, change is inevitable. So are the challenges of problem solving and working through conflict. This is the only way companies can be successful is by learning from things that don't work, supporting each other to improve our technical output as well as our work style. Mapbox is no different than any other start-up in that regard. So the only "con" would be, if you are someone who needs a more predictable, corporate-type environment, a start-up in general might not be right for you. I've been in many and am not upset by change.