In the early 2000s in college I wrote a basic terrain renderer in C++ and OpenGL. It randomly generated some textured terrain, and had some basic features like you could move the camera and look around. Nothing super impressive.

A few months later I landed a 16-month internship on a team writing an OpenGL ES driver. There were 160 applicants, but the hiring manager said I was the only applicant who had actually played around with OpenGL.

It was a great job and I learned a ton.