This article describes the challenges and opportunities encountered in designing an electronic interface for quantum processors. It focuses on the use of standard CMOS technology to design and fabricate integrated circuits (ICs) operating at cryogenic temperatures. The article also focuses on spin qubits possibly operated in the high milli-Kelvin or even in the low Kelvin domain. To realize a spin qubit, a single electron is isolated in an extremely small site on the surface of a semiconductor die. A large magnetic field is applied to ensure that the spin-up and spin-down states of the electron correspond to distinct energy levels. Those two states are then used to encode the qubit quantum states.