Minus One

Upload a song, get it split into vocals, drums, bass, guitar, piano and rest on a serverless GPU, then mute the one you play. A custom multi-track Web Audio engine keeps all six stems in sync with per-track faders, so the band plays everything except your part. Scoped one-hour upload tokens, same-origin stem proxying, rate limits and a daily GPU budget keep the pipeline honest.

• ~10 s from upload to a playable six-stem mixer with a warm GPU worker
• Web Audio gain graph with coordinated seeking and drift correction above 40 ms
• Self-built serverless Demucs worker (CUDA image, baked model weights) behind a provider interface with fallback
• 13 unit suites plus Playwright end-to-end flows