What to work through
Work through a live trivia game as a spoken system design interview. Start by clarifying the scope, sketch a working design and explain the trade-offs behind your choices.
- Join a round and see who else is playing before it starts
- See each question at the same moment as every other player
- Answer before the timer ends and learn whether the answer counted
- Watch the scores and the leaderboard change after each question
Constraints to discuss
- Every player gets the same time to answer, whatever their connection
- A tap on an answer shows within 200 milliseconds
- A player can drop for a few seconds and carry on in the same round
- The client cannot learn the answer early or stretch its own time
Need a starting point?
Watch for these common gaps as you prepare:
- Trusting the time each device reports for an answer
- Sending the correct answer along with the question
- Starting the countdown when the question arrives instead of from the server's time
- Removing a player's place the moment the connection drops
- Sending watchers every answer, as if they were players
Why this question is in the collection
These sources connect the problem to company interview reports or preparation guides. They do not guarantee what a company will ask you.
- Reddit: A frontend onsite tip from October 2024 reports a design round on a quiz-like game app UI, and an August 2026 loop included a trivia app design. The handbook words it as a quiz or trivia app, covering client architecture, APIs and performance. It is not stated to be multiplayer.
- OpenAI: Listed by PracHub on 2026-10-10 as a software engineer onsite question: a trivia battle royale with live spectating. An aggregator entry with no candidate narrative, on the full-stack loop, and backend-leaning.
- OpenAI: Listed by PracHub on 2026-10-14 as a software engineer technical screen question: a multiplayer typing race, likened to online chess. An aggregator entry with no candidate narrative, on the full-stack loop, and backend-leaning.
- OpenAI: Listed by PracHub on 2026-09-21 as a software engineer onsite question: online chess with real-time moves. An aggregator entry with no candidate narrative, on the full-stack loop, and backend-leaning.