This is a pragmatic piece of Fowler on the rather dry topic of Object-relational mappings - in short, the attempt to marry an object-oriented code base with a relational data base.
Usually you’d get enough early success to commit deeply to the framework and only after a while did you realize you were in a quagmire - this is where I sympathize greatly with Ted Neward’s famous quote that object-relational mapping is the Vietnam of Computer Science
What Fowler refers to here, is Ted Neward’s article “The Vietnam Of Computer Science”
Mongoose solves the schema part, or typegoose is you want it to generate types on the go as well.
My problem with mongo is that I always end up realising the advantages of SQL down the line, but I guess many of those projects wouldn’t have gotten that far without mongo being so damn nice in the beginning.