Engineering a market maker system demands more than a strategy. You need clean market data, deterministic order management, robust risk controls, reliable exchange connectivity, and operational discipline in deployment and monitoring. This book is a practical guide to designing and building a market maker system in Python. It covers market-making fundamentals, system architecture, market data processing, an order management system, trading engine design, exchange integration, data storage, system operations, testing, and a Git and CI/CD pipeline. Each chapter includes implementation-focused examples written in modern, production-minded Python. The examples emphasise correctness, clarity, and failure handling, with patterns you can adapt for cryptocurrency or traditional markets.