Agreed, I've never understood this. There are lots of good migrations tools around for SQL databases. If people mean "you don't need to run migrations with Mong

Agreed, I've never understood this. There are lots of good migrations tools around for SQL databases. If people mean "you don't need to run migrations with Mongo, you can just start adding fields to documents as they're accessed, and clean up as-needed" then... don't do that. That's how the Mongo DB I am responsible for was managed for most of the last 10 years. It's a nightmare now, we can barely change it at all.