Linear algebra lands in my professional lap surprisingly often, to the point where I ask myself if it's a linear algebra problem fairly early on in the problem

Linear algebra lands in my professional lap surprisingly often, to the point where I ask myself if it's a linear algebra problem fairly early on in the problem solving process. (I'm in GIS) Calculus is unusual, but it does happen. We do have data with time dependent variables, but usually we don't need anything more complicated than ax + b. When I took linear algebra and discrete math in college, my linear algebra professor was amazing and my discrete math professor was terrible. I got an A in both classes, but for the life of me I don't grok how discrete math is applicable to programming, but if someone starts describing a problem they have I'll be like, "have you tried linear algebra?" in the "have you tried turning it off and back on again?" voice. I need to watch one of those lecture series on discrete math.