The YouTube Shorts Editor extension addresses a specific pain point: creating engaging short-form content from longer YouTube videos requires expensive video editing software and time-consuming manual work. This extension brings professional video editing capabilities directly to the browser. The core technical challenge was running ffmpeg in a Chrome extension environment. Using ffmpeg.js (a WebAssembly port of ffmpeg), the extension can perform complex video processing entirely client-side, including trimming, cropping, adding subtitles, and applying effects—all without uploading video data to external servers. The AI features are particularly interesting. The extension uses speech-to-text APIs to automatically generate subtitles, then applies machine learning models to identify the most engaging segments of longer videos for short-form content. Users can review and refine the AI suggestions before final export. The multi-layer editing capability allows users to overlay text, images, and effects while maintaining real-time preview functionality. This required careful optimization to ensure smooth performance even with large video files. Privacy was a key design consideration. All video processing happens locally in the browser, so users' content never leaves their machine. This was technically challenging but essential for user trust. What I'm learning: WebAssembly opens up possibilities for bringing desktop-class applications to the browser, but it also requires rethinking traditional approaches to memory management and performance optimization.