Romero drove a truck for defendant employer entirely within the boundaries of California, but he delivered goods that had been shipped by interstate transportation. Therefore, was a worker engaged in interstate commerce to whose contract of employment the FAA does not apply. 9 U.S.C. 1. The FAA’s exemption of employment contracts of workers in interstate commerce is not waivable. So the employer could not compel arbitration even though the arbitration clause contained language purporting to waive the exemption.