<p>(Note: I’ve never been involved with the design of a cell phone, so I’m talking out of my ass)</p>
<p>Mostly EEs to work on the circuitry and antennas. CompE’s and CS majors to write the codes for the microprocessors in the phone. EE’s and material science guys to process the circuits. </p>
<p>Maybe other industrial designers and mechanical engineers to make the phone look purdy and to make sure it doesn’t fall apart? </p>
<p>Probably the most numerous of the engineers are the guys who write the codes (CS, CompE) followed by the guys who design the circuits (EE).</p>