This example visualizes a hierarchical tree of LinkedIn job postings, showing the structure of companies, locations, and employment types. The D3 v3 layout creates a collapsible tree diagram with pink and purple node circles and curved link paths. The code uses `d3.layout.tree()` for positioning, `d3.svg.diagonal()` for curved links, and click handlers on nodes to expand or collapse child branches. The data is hard-coded as a JavaScript array with company names, locations, and four job types per location.