How I Built Real-Time Multiplayer Solitaire with SvelteKit and WebSockets

I've been working on VSolitaire for a while now. It's a free solitaire game where you can play against other people in real time. No ads. No download. Just open your browser and go. The concept sounds simple: two players get the same deck, same starting layout. Both play simultaneously. You see your opponent's progress live. First to clear the foundations wins. Building it was anything but simple. The tech stack Frontend: SvelteKit with TypeScript. I picked Svelte because the reactivity model fits a card game perfectly. When a card moves, the UI updates. No virtual DOM diffing, no unnecessary re-renders. The game logic runs client-side for responsiveness, and card dragging uses touch-optimized event handlers so it feels good on phones too. Backend: NestJS with Socket.IO for WebSocket connections. The server validates every move, manages rooms, handles matchmaking queues, and tracks scores. NestJS gave me a clean way to organize the gateway pattern for all the real-time events. The hard