This heatmap visualizes career-related data across two categorical dimensions, with each cell’s color intensity mapped to a numeric value using a sequential Inferno color scale. The chart is built with D3 v4, rendering an SVG grid where row and column labels are derived from the dataset’s `group` and `variable` fields. Interactive tooltips display the exact cell value on hover, while the code relies on `d3.scaleBand` for axes, `d3.scaleSequential` for coloring, and `d3.interpolateInferno` for the palette, sourcing data from a raw GitHub CSV file.