The Quantum Electronics Group develops highly sensitive cryogenic sensors, for example transition-edge sensors (TESs) and kinetic inductance detectors (KIDs), to enable precision measurements in a large range of scientific applications. The successful implementation of these novel sensor technologies requires low-noise readout techniques that can scale to size of the required sensor arrays, while simultaneously satisfying the thermal requirements of the cryogenic systems that cool the sensors. The Quantum Electronics Group designs low-noise amplifiers and multiplexing circuits that are optimized for sensors produced both within the Quantum Sensors Division and larger community using low-temperature detectors. To enable the widest adoption of these technologies, the Quantum Electronics Group also designs and builds the custom room-temperature electronics necessary to perform end-to-end readout with these systems.