Client: live streamer (yas_garbage) Role: solo - analysis, architecture, development, delivery

The problem. The streamer collected video links from chat and tracked them by hand, which cost air time and left the audience with no idea what was queued or how long the session would run.

What I built. A local desktop tool with two surfaces: a control panel the streamer uses off-camera, and a transparent overlay embedded in OBS as a Browser Source. Adding a link pulls the title, thumbnail and duration from the YouTube Data API; the overlay updates instantly with the new queue and the remaining total runtime.

Engineering decisions worth naming. Everything runs on the streamer's own machine - no hosting, no accounts, no viewer data leaving the computer. The server listens on localhost only, validates request origin, and keeps the API key out of every page and message it sends. The overlay is strictly read-only and authenticated by a generated token, so a leaked URL cannot modify anything. State is broadcast as versioned full snapshots rather than diffs, which makes the on-air view self-healing after any disconnection.

Delivery. Packaged as a single Windows executable with tray control and optional autostart, covered by an automated smoke suite of ~1,500 checks run against both source and the built binary.

Stack: Node.js, WebSocket, YouTube Data API v3, obs-websocket, vanilla JS/CSS front end, Node SEA packaging.