COSCUP 2026 - Conference for Open Source Coders, Users, and Promoters

Building a DAW or alike across multiple platforms including mobile and the Web has been a challenging task for various reasons. But thanks to recent innovation and development in audio dev. community, it became realistic in 2026.

Through this session we will discuss how cross-platform DAW sequencer engine became realistic, based on my own dev. experience. The topics will include:

• inclusive audio plugin hosting API that covers Android and Web
• audio engine requirements, especially node graphs and real-time audio processing boundary
• GUI interaction approaches on each plugin format
• how parameter updates work, especially across states and presets, among GUI, DSP and host
• requirements on song project data models
• separation of concerns among all these

In the agentic coding era, there are many emerging audio app projects that people used to find impossible to work on. I hope this session will give some guidance and design choices to those who want to build their own DAW or similar audio engines.