Devices under test (DUTs) can be tested in a test system that includes an aligner and test cells. A DUT can be moved into and clamped in an aligned position on a carrier in the aligner. In the align position, electrically conductive terminals of the DUT can be in a predetermined position with respect to carrier alignment features of the carrier. The DUT/carrier combination can then be moved from the aligner into one of the test cells, where alignment features of the carrier are mechanically coupled with alignment features of a contactor in the test cell. The mechanical coupling automatically aligns terminals of the DUT with probes of the contactor. The probes thus contact and make electrical connections with the terminals of the DUT. The DUT is then tested. The aligner and each of the test cells can be separate and independent devices so that a DUT can be aligned in the aligner while other DUTs, having previously been aligned to a carrier in the aligner, are tested in a test cell.