An electronic assembly includes a circuit board that serves as both a mechanical attachment point and signal conduit for electronic components. The circuit board includes at least two modular card connector assemblies disposed on opposing surfaces of a mounting region of the circuit board. Pin sets of the modular card connector assemblies are connected together via corresponding through holes extending between the opposing surfaces in the mounting region. Further, pins of one or both the modular card connector assemblies may be connected to other electronic components disposed at the circuit board via lateral traces. One or both of the modular card connector assemblies can comprise a modular card socket to removably couple with a modular card. Alternatively, one or both of the modular card connector assemblies comprises a pin interface assembly that is integral to or otherwise fixedly attached to the modular card.