Solution: Work with Transactions and the Multi Module

cs = Ecto.Changeset.change(%Album{title: "Bag's Groove", artist_id: 1})
  |> Ecto.Changeset.validate_required([:title])
Repo.transaction(fn -> 
  case Repo.insert(cs) do
    {:ok, _album} -> IO.puts("Album insert succeeded") 
    {:error, _value} -> Repo.rollback("Album insert failed")
  end
  case Repo.insert(Log.changeset_for_insert(cs)) do
    {:ok, _log} -> IO.puts("Log insert succeeded")
    {:error, _value} -> Repo.rollback("Log insert failed")
  end
end)