Pros
Very friendly place to work. Free lunches part of the week. Nice views in the NYC office. Great CFO/COO keeping the finances sound. Great legal team. I've also had very good experiences with the HR team, although I know that may not be a universal experience.
Kontras
The company is way too political. The CEO has a habit of broadcasting his personal political opinions on the company-wide mailing list or at all hands meetings. Employees gang up on those who dissent politically in Slack. Or they report political dissenters to HR for making them feel "unsafe". Much of middle management in engineering is very inexperienced. This is due to a hiring policy during MongoDB's hypergrowth phase where almost all new hires came through the internship program. MongoDB is the only company much of engineering middle management has ever worked at. Higher up management seem to go out of their way to dismiss negative feedback given through Culture Amp surveys. One time, after receiving a lot of negative feedback, the head of Cloud Engineering dismissed it all as being due to a decline in the stock price. There's way too much process in engineering. People have been complaining about it for years, and yet little changes. Engineering skill varies widely. There's some very excellent engineers at the company, and a whole lot of average or even rather poor engineers.