A d3.js heatmap displays career data across two categorical axes, with each cell colored using an inferno sequential scale. The visualization maps group and variable labels to x and y coordinates, while the cell intensity reflects a numeric value. Hovering a cell reveals its exact value via a custom tooltip. Built with d3.js v4 and the d3-scale-chromatic library, the SVG chart loads data from a remote CSV file and includes axis labels, a title, and a subtitle.