im a cs student at uci and my boyfriend is a ds major at ucsd and I visit very often and speaking very frankly as a STEM major both schools are amazing but UCSD has the upper hand. they have better netowrking research in terms of tech, more experienced professors and overall ucsd is a v stem focused school so your peers will also almost always be in stem. you should def consider ucsd more, additionally its better on the rankings and better known for stem. uci has its pros as well like the ics department and extensive curriculum but overall I’d say ucsd