While people often don't have to do the explicit differentiation and integration taught it calculs that doesn't mean you aren't using knowledge learned in a calculus class.

I often think about rates flows and how they relate to each other. For example to do monitoring we count the total number of messages received in each task at a given time, then use the diffrence to get a rate. That is basically differentiation and understanding calculus makes it easier.

The other thing you acquire from doing Calculus is problem solving experience, figuring out how to apply various approaches to a problem to get to a desired solution. In this way calculus strengthens your brain similar to how a sports player might do weight lifting even if their sport doesn't involve lifting heavy objects.