A connector system includes an interface connector having a housing having a main body holding a contact array therein. The housing extends between a front end and a back end along a mating axis. The housing includes a cavity therein open to the front end and open to the back end. The cavity is situated proximate to a side of the housing. The cavity has a receiving channel open to the side of the housing. The receiving channel has mounting shoulders at least partially extending therein. The interface connector also includes a fastener having a retention surface. The fastener is configured to be side-loaded into the receiving channel through the side of the housing. The mounting shoulders engage the fastener within the cavity to limit transaxial movement of the fastener along the mating axis.