Multiplayer quiz platform with server-enforced integrity. Designed an anti-cheat architecture combining server-side session tokens, timer validation on the backend (client timers are advisory only), and activity monitoring to flag suspicious patterns.

Social graph with following/followers, per-quiz leaderboards with concurrent write protection, and a content authoring system that lets creators publish and manage quiz libraries. Fullstack: Next.js, Node.js, MongoDB, with real-time events for live scoring.