I'm currently in school pursuing a degree in game development & programming, and I'm looking for some direction on getting started making a portfolio for gameplay programming. Firstly, what kind of projects or work samples should I even put in such a portfolio? I'm guessing something along the lines of small completed games (either solo or as part of a team) or maybe even feature demos, something just to show that I know how to program gameplay mechanics. Additionally, I've heard that personal projects generally are more interesting to employers, but really all I have so far is stuff I've made for school. I'm juggling a full time job and going to school online, so at the moment I don't have a lot of free time to do side projects. I'll have more spare time (and energy) after I finish up with classes early next year. So far I've done all my game programming in Unreal Engine 4, so that's really all I know how to make games with.
Secondly, how should such a portfolio even ideally be presented? (A webpage linking to code repos? Should I include any demo videos of my work? Should I just focus on showing the code? etc.)