Differential equations are not advanced math. If you were complaining about topology or having to prove something then that is advanced math. When I was taking a grad school test on OS ( I forgot the exact topic) it involved something about scheduling and it was much shorter and elegant to answer by using limits than having to explain the answer with lots of words.
As a professional who is been in the software world for at least 12 years, at this point in my career I do not need that kind of math. However , understanding that kind of mathematics as well as the numerical algorithms to go with them is very useful as many fields use them. If you don't know the basic mathematics expected of an undergraduate you will be cutting yourself from many opportunities.