Pretty much anything dynamics related. Starting basic displacements, velocity, acceleration integration for simple dynamic systems to more complicated equations for wind and spinning rotor interaction induced vibrations in wind turbines.
If you do not work with dynamics, for statics there are still a lot of encounters with deferential equations. Euler-Bernoulli Beam theory or plate and shell theories can be used for times when you want to solve more complex problems for which predefined equations do not exist and you do not have access to expensive fea software.
I recently had to do linear algebra for the first time ever irl. I’ve been out of school for ~15 years. I was trying to make a rotation matrix to transform some points in 2D space. It took me a very long time to remember how it’s performed yet alone “transformation matrix” which is something I’d never heard of before. I got my code all working and was so proud, then later found that one of the r packages I was using could have just solved it all automatically :/
You can always try to pivot from project management to actual engineering. I am load engineer for wind turbines and everything is time dependant and dynamic. For past 10years i use every bit of math I learned is school and uni.