The triangle end bits of that 3rd guy's staff remind me of those videos of people coding in raw rendering script for Vulkan or OpenGL. "HAHA Yes! The triangle shows a gradient between the primaries! My custom game engine will be amazing no doubt!"
1st guy is programming and building of world or logistics. 2nd is geometry and meshing. 3rd is the shader colors and render pipeline. 4th is post processing and reflections.
