This dashboard presents a multi-view analysis of Fitbit activity and sleep data, with a scatterplot, flow lane, parallel coordinate chart, correlation matrix, and heatmap for exploring multivariate relationships. Users can brush on plots to filter records, select clusters, and upload their own CSV files via a file picker. Built entirely with D3 v7, it leverages the brush API, linear scales, axis generation, data joins, event handling, and categorical color schemes to render interactive SVG visualizations.