A D3.js job typically involves using the D3.js library to create dynamic and interactive data visualizations for web applications. Professionals in this role often work with JavaScript, HTML, CSS, and SVG to manipulate data and render charts, graphs, and other visual elements. They may collaborate with data analysts, designers, and developers to present complex information in an intuitive and visually appealing manner. Strong knowledge of data structures, algorithms, and front-end development is usually required.