A stacked bar chart displays technology job counts across experience levels, using categorical colors to distinguish entry-level, intermediate, senior, and expert segments. The visualization loads CSV data with d3.csv, stacks series with d3.stack, and maps values through d3.scaleBand and d3.scaleLinear for axes. Hover interactions trigger a tooltip showing the exact category and count for each bar segment, rendered as SVG rectangles within the chart container.