In a recent project, I worked on a small web application where I used JavaScript to enhance user interactions by manipulating the DOM. The task involved creating a dynamic form that responded to user inputs in real-time. For instance, as users filled out certain fields, additional related fields would appear, providing a more intuitive and streamlined experience. One of the challenges I faced was ensuring that the DOM updates were efficient and didn't cause any lag, especially on slower devices. To address this, I optimized the JavaScript code by minimizing reflows and repaints, and I used event delegation to manage event listeners more effectively. This experience taught me a lot about performance optimization and the importance of writing clean, efficient code.