HoverNotes

Privacy-first AI video learning platform eliminating context-switching

Description:

Founded and leading technical development of HoverNotes, a groundbreaking privacy-first AI video note-taking platform that eliminates context-switching in video-based learning. The platform features a sophisticated three-tier architecture (browser extension + web app + AI backend) enabling note-taking on any video platform while maintaining complete user privacy through local Obsidian vault storage.

Project Duration:

January 2025 – Present (Founder & Technical Lead)

Key Technical Achievements:

  • Universal Video Integration: Built advanced video detection system working across all platforms (YouTube, Udemy, LinkedIn Learning, Bilibili, etc.) using DOM mutation observers and cross-origin message passing
  • Privacy-First Architecture: Implemented local-first storage with direct Obsidian vault integration using Chrome's File System Access API - zero cloud data collection
  • Browser Extension Mastery: Chrome Manifest V3 implementation with advanced permission management, service workers, and floating iframe-based editor
  • AI-Enhanced Learning: Integrated multi-modal processing with real-time streaming note generation and LangGraph reasoning agents
  • Global Scale Engineering: 45+ language localization with AI note generation adapted to linguistic nuances and cultural learning styles
  • Screenshot Integration: Automated video frame capture with precise timestamp correlation and organized storage

Technical Stack:

  • Frontend: Next.js 15, React 19, TypeScript, Lexical Editor (Meta's rich text framework)
  • Browser Extension: Manifest V3, File System Access API, tabCapture API, Cross-origin messaging
  • Backend: Python FastAPI, LangGraph, Docker, PostgreSQL
  • AI/ML: Custom reasoning agents, Multi-modal video processing, Real-time transcription
  • Infrastructure: Hetzner Cloud, Docker Compose, Nginx, SSL/TLS automation

Business Impact:

  • Addressing the $68B online education market with privacy-first solution as data protection becomes critical
  • First platform combining universal video compatibility + AI enhancement + complete privacy
  • Eliminated context-switching between video watching and note-taking applications
  • Empowering learners with complete control over their educational data

Innovation Highlights:

  • Technical Innovation: Single extension working universally across all video platforms without platform-specific code
  • Privacy Leadership: Local-first architecture in era of cloud-dependent note-taking solutions
  • AI Enhancement: Multi-modal processing beyond simple transcription available in existing tools
  • User Experience: Seamless note-taking overlay that never interrupts video learning flow