Systems

A bidirectional relationship (users know their rooms, rooms know their users) has to be updated under a single lock, or readers will catch it half-done.

A terminal BitTorrent client with a process-per-torrent architecture, where every command works as a scriptable one-shot invocation or an interactive TUI.

A thread-safe Go library providing a reusable Room-User architecture for real-time systems like chat and multiplayer games.

Led an online poker platform with advanced tournament features and an event-driven backend for thousands of concurrent players.

Five-plus years on a real-money real-time poker platform: game logic, load testing at 21,000 simulated concurrent players, disaster recovery, and a PHP → Node.js migration.