Thrasher's Call

Good migrations hide and abstract their inner change to limit outside impact.

Good migrations don’t break others’ expectations; they must respect contracts.

Good migrations keep back compatibility with past behaviors, so others need not change.

Good migrations are safe; they always have a way to revert to previous state.

Good migrations don’t take long; they must be quick, to avoid impeding business operations.

Good migrations are, to me, for the birds – or, well, machines; I’ve grown best in breaking changes.