An interposer including stress-engineered nonplanar microsprings may provide interconnection of bonding pads of electronic structures disposed above and below the interposer. The lateral offset between an anchor portion of a microspring disposed for contact at a bottom surface of the interposer and the tip of the microspring located in a free portion of the microspring for contact and deflection over a top surface of the interposer permits the interconnection of devices having different bonding pad pitches. Microspring contacts at the free portion permit temporary interconnection of devices, while solder applied over the free portion permit permanent connection of devices to the interposer.