A Three.js job involves developing 3D graphics, interactive visualizations, and web-based experiences using the Three.js JavaScript library. Developers in this role work with WebGL, shaders, and mathematical concepts to create immersive applications for gaming, simulations, architecture, and more. Responsibilities often include optimizing performance, integrating assets, and collaborating with designers to bring 3D content to life. Strong knowledge of JavaScript, 3D modeling, and rendering techniques is essential.