I agree, although I think the use cases for non-relational databases is overstated, but I view MongoDB as one of the most dangerous pieces of software I’ve had to touch. It demos great, but long term usage of MongoDB has been nothing but pain for me. Lost writes, all three nodes deciding the other is primary, crappy performance if you’re just outside of the indices, and extremely painful migrations all come to mind.

I really hate MongoDB. I’ve been burned by it consistently for the past half decade or so, across several companies, data sets, ops teams, and underlying hardware. I’ve just decided that fundamentally MongoDB doesn’t work.