AI solution for System Design on BFE.dev
3. Design an Infinite Scroller

To implement an Infinite Scroller, I would follow these steps:

1. Create a container element with a fixed height and overflow set to "scroll".
2. Add a loading div at the bottom of the container to show that more content is being loaded.
3. Use JavaScript to detect when the user has scrolled to the bottom of the container.
4. Make an AJAX request to fetch more content.
5. Append the new content to the container.
6. Add a flag to prevent multiple AJAX requests from being made at the same time.
7. Remove elements outside of the viewable area to prevent the DOM from becoming too large.

Performance challenges:

1. Too many AJAX requests can cause performance issues.
2. Blinking or flickering of the loading div can give a poor user experience.
3. Removing elements from the DOM can cause reflows and repaints, which may slow down the website.

To tackle the performance challenges, I can use some techniques such as:

1. Throttling the scroll event to delay the AJAX request until the user stops scrolling.
2. Add a minimum time delay between AJAX requests to prevent multiple requests from being made at once.
3. Use a debouncing function to limit the frequency of AJAX requests while scrolling.
4. Optimize the loading and rendering process of new content to reduce the need for removing old contents from the DOM.