D3 v4 renders a time-series line chart tracking VizHub user growth from 2018 to 2022, annotated with key milestones like a Medium post and the 2.0 Kickstarter. The SVG visualization uses d3.scaleTime and d3.scaleLinear for axes, d3.axisBottom and d3.axisLeft for ticks, and d3.line for the path. Circles mark each data point, while d3-svg-annotation adds contextual callouts, all styled with custom CSS for gridlines and axis labels.