Granted I really don't spend my time evaluating databases rigorously, but I find claims that MongoDB is more performant than Postgres really difficult to believ

Granted I really don't spend my time evaluating databases rigorously, but I find claims that MongoDB is more performant than Postgres really difficult to believe. It sounds like a skill issue to me. MongoDB is technical debt, it has it's place for when you don't know what you're doing and you just need to throw your data somewhere. Eventually you're going to grow to a point where the overhead of not using real data structures is going to cease to be worth it. (I realize this is directly contrary to what's stated in the article, but who are you gonna believe, MongoDB or a random HN commenter? :)