Electrical connector system

An electrical connector assembly comprises a circuit board (12) having vias (54) each extending at least partially through the circuit board (12) along parallel via axes (106). An electrical connector is mounted on the circuit board (12). The electrical connector comprises a plurality of variable depth signal terminals (26) configured to extend different depths into respective ones of the vias (54). The signal terminals (26) each have a terminal axis (134). The signal terminals (26) are arranged in pairs carrying differential pair signals, with the signal terminals (26) of each pair extending to the same depth in the respective vias (54). The terminal axes (134) of the signal terminals (26) of each pair are offset with respect to the corresponding via axes (106) along a majority of the depth of the signal terminals (26) within the vias (54).