Finished my Unity senior SWE loop in early June 2026. The system design round was one hour, two interviewers, and they gave me about two minutes of framing before just... asking the question. No warmup, no pleasantries. I kind of respect that actually.
The prompt was designing a real-time leaderboard for a multiplayer game. Classic, but they pushed hard on scale. They wanted specifics on read/write ratios, how I'd handle fan-out when a top-ranked player's score changes, what happens during network partition. Definitely game-engine-aware questions. This is not a generic FAANG system design. If you don't know what a game tick rate is or why latency in a physics simulation matters, you'll feel it.
A few things that stood out:
Depth over breadth. They kept interrupting to drill down on whatever I was hand-waving. I mentioned Kafka offhand and immediately got: 'walk me through your partition strategy.' Have answers ready one level deeper than what you plan to say.
They care about tradeoffs explicitly stated. Not just 'I'd use Redis' but 'I'd use Redis here because the read pattern is hot-key heavy and we can tolerate eventual consistency in the leaderboard display, but I'd add a write-through cache invalidation because...'. The 'because' matters.
Game domain knowledge helps. I don't have a game dev background but I'd read up on how Unity's DOTS and multiplayer networking stack works. That framing helped me speak their language. Level = senior, no formal FAANG-style leveling rubric that they shared, but the signal-gathering felt like it mapped to L5/L6 territory.
Two interviewers took turns asking follow-ups. They didn't feel adversarial but they were definitely stress-testing assumptions. Total: 60 minutes, no buffer, ended right on time. No whiteboard (remote), used a shared doc.
Happy to answer specifics if you have them.