Engineering Music Streaming

for Millions of Danish Users

YouSee Musik

Making 100 Million Songs Feel Personal

As Tech Lead for the Apple platform, I helped evolve YouSee Musik into a modern streaming experience across iPhone, iPad, Apple Watch, CarPlay, and the broader Apple ecosystem.

YouSee Music gives subscribers access to more than 100 million tracks, personalized recommendations, curated playlists, offline listening, live radio integration, and seamless playback across devices. The platform serves a large audience in Denmark and competes in a space dominated by global streaming services.

View in the App Store

Check out the product page (Danish)

Key focus on

  • Shared native platform code across all devices
  • Offline downloads and synchronization
  • CarPlay integration
  • Apple Watch companion experience
  • AVFoundation and audio playback architecture
  • Modularization and dependency injection
  • Team leadership and technical strategy
  • CI/CD and release automation
  • App performance and startup-time improvements
  • Feature flagging and experimentation infrastructure

Project Outcome

Future Enhancements

  • Expand personalization capabilities using listening behavior, contextual recommendations, and machine learning models.
  • Improve content discovery through richer editorial experiences, smart playlists, and personalized home screen sections.
  • Enhance cross-device continuity to provide even smoother transitions between iPhone, iPad, Apple Watch, CarPlay, and other connected devices.
  • Introduce more real-time experiences such as collaborative playlists, social listening features, and live content integrations.
  • Continue optimizing application performance for large content catalogs and lower-end devices.

Technical Evolution

  • Further modularize the codebase to improve development velocity and reduce coupling between features.
  • Increase adoption of Swift Concurrency (async/await) alongside Combine where it provides simpler and more maintainable asynchronous workflows.
  • Expand automated testing coverage across business logic, UI flows, and streaming scenarios.
  • Improve observability through enhanced analytics, performance monitoring, and crash diagnostics.
  • Strengthen feature flagging and experimentation capabilities to support safer rollouts and data-driven product decisions.