This article, authored with the help of Marie Starck, provides a comprehensive guide on building a customizable slider in React using the react-slider library, an open-source component developed by Zillow in 2021. The guide includes step-by-step instructions on setting up a React project, installing the react-slider library, and rendering the default slider component. It explains the anatomy of a slider, detailing how to customize its components such as the track, thumb, and marks using CSS and React props. The article emphasizes the flexibility and customizability of react-slider, likening it to a lower-level framework similar to d3, which requires user-defined styling for visibility and functionality. By demonstrating how to implement features like dynamic marks and interactive thumbs, the guide ensures that the reader can create a fully functional and aesthetically pleasing slider. Additionally, it offers a link to a GitHub repository for those who want to view or follow along with the completed project.