How I Built a Lightweight Turn-Based Relay Server with Java 25 Virtual Threads And Reconnect Handling

Turn-based multiplayer is deceptively hard. Here's how I designed a simple, fast, and cost-effective relay backend that auto reconnects dropped clients and keeps egress + resource usage low. Building reliable turn-based multiplayer is painful. Enforcing turns, hiding hands/decks, handling votes, and especially managing disconnects and crashes can eat weeks of dev time. I wanted something lean that "just works" for Unity and other clients without massive infrastructure costs. So I built TurnKit R