Pros
I have just completed 4yrs with MongoDB in India, SE Asia & Middle East and my overall experience has been nothing less than "Wow". We are growing very fast but still have that basis of a startup culture, high potential growth environment. I myself have grown personally & professionally over the period of time and there is so much still to do. There is honestly no reason for anyone to look outside for job as there is a very open culture with so many different fields to work in. MongoDB is on the cusp in database field and is poised for growth because of what we offer as a software product. Management is so much reachable and open to listen and change basis the feedback.
Cons
Its a very open, competitive & performance driven environment so you can't bluff your work here.