WebSocket Fanout for Earnings Prints — MU Night Checklist

Micron’s Sep 30 AMC print is a load test you can put on the calendar. Checklist:

1. Shard subscriptions by symbol, not one global multiplex dump to every phone.
2. Cap client resubscribe storms after reconnect.
3. Prefer server-side coalescing for last trade + alert banners.
4. Measure JS thread hitch rate on a mid-tier Android during a replayed burst.

If your fanout only works when VIX is quiet, it is not ready for single-name event nights.

Want a production reference? Open Stock Picks — the paper-trading app this studio ships against.

Not financial advice; engineering notes only.