Polymarket's New Trading System Nex Opens Sandbox Testing, Targeting Mid-December Launch

November 13 — Josh, Polymarket's Vice President of DeFi Engineering, announced on X that Nex, the new trading system rewritten in Rust, has opened for sandbox testing. Over the past week, the system has mirrored production orders in shadow mode to verify latency, load stability and matching accuracy, and it has not yet gone live officially.

Internal test data disclosed shows that P99 order latency has fallen from 1.55 seconds on the existing central limit order book (CLOB) to 3.76 milliseconds, though this metric is not end-to-end latency. The team plans four weeks of shadow testing; if it runs well, launch is expected in mid-December, and WebSocket improvements may roll out earlier.