Prediction markets like Polymarket are experiencing unprecedented global traffic spikes. For a backend engineer, building a platform where thousands of users concurrently buy, sell, and trade shares on real-world outcomes is a serious architectural challenge. If you try to build this using traditional sports-betting logic or heavy framework wrappers, your RPC nodes will choke, and your database will suffer from catastrophic race conditions. In this deep dive, we’ll analyze how to design a high-load, zero-risk core architecture for a prediction market engine using clean PHP 7.4+ (OOP), Vanilla JS, and optimized database transactions. ## 1. The Core Mathematical Model: Why Admin Cash-Drop is Impossible Unlike bookmakers where the platform bets against the user and risks its own capital, a true prediction market utilizes a dynamic pool recalculation model . The platform acts purely as an escrow and escrow keeper. The Rule: Winners take payouts directly from the pool of losers.…