A communication system includes a host circuit board and an interposer assembly coupled to the host circuit board having an interposer substrate including an host circuit board contacts at a lower surface and module contacts at an upper surface. The communication system includes an optical pluggable module having a mating interface along a bottom of the optical pluggable module facing the interposer assembly. The optical pluggable module includes a module substrate and optical engines coupled to the module substrate with optical fiber cables extending from the optical engines to the cable end. The module substrate has module substrate contacts at a lower surface of the module substrate being electrically connected to corresponding module contacts of the interposer assembly at the upper surface of the interposer substrate.