This example demonstrates a bar chart visualization of population by country for 2015, using a dataset loaded from a GitHub gist via d3.csv. The chart displays countries on the x-axis sorted in descending order of population, with population values mapped to the y-axis. It is constructed programmatically using the Vega-Lite API (vl) to define the bar mark and encodings, then rendered through Vega and Vega-Lite engines. The code also applies a custom configuration for axis styling and uses Vega-Tooltip for interactive hover details.