This combined bar and line chart displays monthly average notifications as light-blue bars on a left axis, with the average productivity score overlaid as an orange line on a right axis, facilitating comparison between the two metrics across time. The visualization aggregates daily records from a digital usage dataset by month using `d3.rollup` and `d3.timeMonth.floor`, then renders the result in SVG with D3 v7’s `scaleBand`, `scaleLinear`, `axisLeft`, and `line` generator.