Design
Multiplayer Tic-Tac-Toe with Matchmaking
Design a real-time multiplayer Tic-Tac-Toe game with matchmaking, live moves, and rematches.
This is a Low-Level Design (LLD) problem. New to LLD vs HLD? Start here.
01 - Why interviewers ask this
Adding real-time matchmaking and server authority to a "toy" game tests whether you understand why clients should never be trusted to self-report game outcomes.
02 - Where this system exists in the real world
You interact with this design every day.
Real-time multiplayer casual game platforms
Matchmaking systems for skill-based games
Game server architectures with authoritative state
03 - What you'll master
Solve this once. Know it forever.
Implement a FIFO matchmaking queue
Keep the server authoritative over game state
Handle player disconnects mid-session gracefully
04 - What you'll design
6 functional · 2 non-functional requirements.
Match two waiting players into a new game session
5 more requirements inside
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05 - Companies that ask this
You may face this exact question in your next interview.
Ready?
Open the canvas.
Design it yourself.
See all requirements, use staged hints, run your code, and compare with community discussions - all on the same canvas.