There is no such thing as early employment, but you can get employment in advance, that is to say, if the enterprise wants to hire you, you can apply directly to the school without taking part in the internship arranged by the school, but the real graduation still has to wait until the moment when the diploma is issued. The graduation certificate is issued at the same time and will not be issued to you separately. You can go back to school to get a certificate after graduating from early employment.