Yeah you compare your intended state for prod to what you currently have on prod, and generate the differences. It's still a "migration", the difference is it'

Yeah you compare your intended state for prod to what you currently have on prod, and generate the differences. It's still a "migration", the difference is it's generated from a direct comparison to production rather than a crude reconstruction of the database's history. Checking production directly is much more robust (more testable, changes made outside the context of the migration tooling are no problem) and simpler because it you don't need to maintain a historical migration chain - there's only ever one migration script to consider. And using a diff tool directly on the database means you can support database features that aren't directly supported by your ORM.