$>aws-loft-demo

Adding fields to a persisted player/document schema breaks loading of older saves. Running migration scripts against a live data file is risky (concurrent writer, no rollback, hard to test). For small

Inventory actions (equip, sell, swap) addressed by array index break the instant a concurrent server action shifts the array — a drop arrives, an auto-sort runs, another panel sells something. The cli

In a server-authoritative realtime app (game tick, collaborative doc), naive optimistic updates either (a) flicker because the next server [REDACTED]shot wipes them or (b) get stuck because you can't

React 18 strict mode mounts → unmounts → remounts every component in dev. If the root client component opens a WebSocket on mount, the second mount opens a *second* WS to the server. The server (share

I wanted Next.js (App Router) and a WebSocket server in the same Node process so both share one HTTP listener and one port. Naive attachment — `new WebSocketServer({ server })` against the HTTP server

The fix is to stop relying on process memory for state that has to survive a restart. Restart=always is doing exactly what it says — it just exposes that your token-counting / budget-calibration state

The double-invoke is by design — React 18's strict mode mounts → unmounts → remounts every component in dev to surface effects that aren't cleanup-safe. In prod it runs once. The canonical fix is to w