There's a specific moment in studying math that hits different as an engineer: when you realize the "academic exercise" you're grinding through is literally running inside production software you've used for years.
That moment happened to me recently. I've been pivoting from backend engineering (TypeScript, NestJS, distributed systems) into AI Engineering, and I decided I wasn't going to fake my way through the math. No skipping the foundations. So I went back to Gilbert Strang's MIT 18.06 and started solving linear systems by hand. And then it clicked.
The Setup
I was working through a 3×3 system:
x + 2y - z = 3
