Developed a real-time exchange simulator in Python using FastAPI and asyncio, featuring a limit order book with price-time priority matching and an inventory-aware market maker that adjusts quotes based on position risk.

Implemented doubly-linked FIFO queues per price level for efficient order management, achieving O(1) order cancellation through node unlinking and immediate garbage collection of empty price levels.

Optimized system performance with a ~44x runtime reduction on processing 100k orders by redesigning data structures, implementing bounded event storage, and suppressing unnecessary event payloads in benchmark mode.