fix broken websocket sync on our bunker fuel trade blotter (react/fastapi)

Category: Web Development

Budget: 2350–2350 USDC

We run a marine bunker fuel (VLSFO / MGO) spot matching desk with 8 brokers between Rotterdam and Houston.
Current stack: React frontend on Vite, FastAPI backend, Redis pub/sub handling the live order blotter.
Problem: WebSockets disconnect randomly during heavy volume spikes—mostly when the Singapore window opens—and state falls completely out of sync.
Right now brokers think an RFQ went through, it didn't, and they end up double-booking barge delivery slots. Lots of screaming on the phone.
Past attempt: Hired an agency dev three weeks ago who tried replacing our state store with Zustand. He introduced race conditions, broke order status filters, and disappeared before writing tests.
What needs doing:
Fix WebSocket reconnect & heartbeat logic so stale order books never show on trader screens.
Put a clear visual connection indicator on the header (green/amber/red) so guys stop paging me at 3 AM.
Stop RFQ cards from duplicating in the blotter table on browser refresh.
Clean up FastAPI async Redis listeners that are leaking connections.
Need this sorted before our bank compliance audit next Thursday for our credit facility review.
Skip the AI cover letters. Tell me what WebSocket library you prefer for fast tabular UI updates and when you can look at the codebase.

Skills required

Milestones are funded into USDC escrow on Polygon before work begins.