The 60-second answer
Frame the goal as useful, relevant, safe comments—not raw engagement. Generate eligible candidates, then rank with user/comment/author/post interactions, content semantics, freshness, quality, safety, and conversation context.
Build the answer in this order
Frame the goal as useful, relevant, safe comments—not raw engagement.
Generate eligible candidates, then rank with user/comment/author/post interactions, content semantics, freshness, quality, safety, and conversation context.
Correct for position-biased implicit labels and evaluate ranking quality together with hides/reports, diversity, latency, and creator/user outcomes.
Run guarded experiments and monitor feedback loops so already-prominent comments do not monopolize future training labels.
A useful interview mental model
This is the shape of a strong answer—not a script to memorize.
Senior-level signal
- Discuss multi-objective ranking, exploration, position-bias correction, and causal evaluation.
- Treat integrity/safety constraints as first-class ranking requirements, not an afterthought.
What the interviewer is really testing
Likely follow-up questions
Common weak-answer patterns
- Jumping to a model before defining the product contract.
- Listing components without bottlenecks, metrics, or failure handling.
- Ignoring data quality, serving latency, monitoring, and iteration.