Pros
Coming from a pretty challenging web dev shop, the difference in culture and workload is pretty noticeable. Standups only a couple times a week versus every morning, with plenty of space (and trust) from your team to get your work done. There is a culture that is generally supportive/aware of psychological health and mindful of it in daily interactions. Pay is pretty good too, especially for remote roles. Ramp up times are slower and generally forgiving, especially if you are new to the MongoDB ecosystem. They have the process almost down to a science.
Cons
Knowledge gained in certain roles at MongoDB may feel highly specific and non-transferable at times. It is going to take extra work to make sure you stay relevant in the job market by using the very specific skills you gain at work (which will be many) to keep your other skills sharp.