Perpetual Engine Series Part 2: Real-Time PnL...

In Part 1, we explored Liquidation Logic—the safety net that prevents exchange insolvency. But for that safety net to work, the engine needs a precise, real-time "heartbeat." That heartbeat is PnL (Profit and Loss). Get this calculation wrong, and traders lose money unfairly. Get it right, and the system stays trustworthy at scale. Here’s how I built a PnL system in Rust that handles thousands of updates per second with zero rounding errors. 1. What is PnL? (The Engine's Core Metric) PnL is simp