This repository is a curated showcase of advanced data visualizations built with Vega, Vega-Lite, and Deneb for Power BI. It contains 30+ standalone JSON specification files that each implement a complex interactive chart (e.g., Gantt charts with dependency arrows and collapsible phases, parliament charts with semicircular layout, force-directed graphs, convex hulls, beeswarm plots, animated bar chart races). The data used is either embedded inline or provided as separate CSV/JSON files covering real-world topics such as S&P 500 companies, UK COVID-19 rates, bank failures, military spending, and monarch timelines. While not a traditional software application or data pipeline, the repository serves as a reference library of reusable Vega patterns and declarative visualization logic. The specs demonstrate advanced Vega features including signal-based interactivity, data transforms (flatten, window, force), custom SVG paths, and dynamic layout algorithms. The repository is primarily a portfolio/educational resource, with no build scripts, tests, or dependency management. Some external data URLs and hardcoded static datasets may cause freshness issues, but the core visualization patterns remain stable and adaptable.