Schema migration is hard. Skeema looks cool. Aquameta's idea with schema migration is to treat the schema as data, so that each table is a meta.table table, each view is a row in the meta.view table, each column... etc. So when version control checks out a new version of the project, if columns say were added, they're just inserted at runtime. Checkout prioritizes meta entities so they happen first and in a sensible order [1] so the migration happens first. This does technically work for all scenarios (I think!), but in the case of say a column rename, it would naively delete all the values and then have to re-set them per row, which could be a big inefficiency. It would still work just fine for smaller tables though. Alternately some kind of optional migration script per commit was another idea.