This example presents a reusable D3 v7 scatter plot that visualizes a small CSV dataset of individuals, plotting their age against their ID number. The chart uses the `d3.scaleLinear` API for both axes, with points rendered as circles using the D3 `.join()` pattern for efficient SVG creation. The code defines a chart factory function, following Mike Bostock’s reusable chart design, allowing customization of the x and y columns and point radius. The data is loaded via `d3.csv` with `d3.autoType` for automatic type inference.