Versioned migrations for the stints table — Oban-style. In your application's migration:

defmodule MyApp.Repo.Migrations.AddStint do
  use Ecto.Migration

  def up, do: Stint.Migration.up()
  def down, do: Stint.Migration.down()
end

up/1 migrates to the latest version and is a no-op for versions already applied, so future stint releases with schema changes just need a fresh migration calling up/1 again.