I built TGDown , a Chrome extension that adds download controls for images and videos in Telegram Web. The original product goal was simple: when users browse a Telegram chat, channel, or search result, they should be able to save media without repeatedly opening the viewer, fighting the context menu, or handling every item one by one. The implementation was less simple. Telegram Web is a large, fast-moving single-page application. An extension needs to add UI without breaking scrollin...