PlayStation·Data Scientist·Technical Phone Screen
Jun 2026
Senior DS interview at PlayStation, focused entirely on experimentation. Two meaty questions, both with follow-ups that kept branching. The social network effects one in particular had a lot of moving parts and I'm not sure I covered all of them well.
- The experimentation platform ran an A/A test with an intended 50/50 split, but the observed ratio came out 51/49. Is that a problem, how would you test whether the imbalance is statistically meaningful, and what root causes would you dig into before trusting future A/B results?
- You want to test a new feature where friends can send each other virtual gifts, with the hypothesis that gifting increases engagement. Define your primary metric, guardrail metrics, and success criteria. Then walk through how you'd design the experiment, what randomization unit you'd pick, how your approach changes if the friendship graph is extremely dense, and what validity threats you'd be worried about.
“My first instinct was to say 'no, that's fine, noise happens' and I think that's basically right but I fumbled the follow-up about how to actually test it.” The rest of the author's notes on Data Scientist interview at PlayStation, Technical Phone Screen round, covers how they worked through the question, what the panel pushed back on, and what they would do differently.
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