Data scientist interview prep, head-to-head
Generic copilots fall back to LeetCode hints. DS rounds need different muscles: window functions, p-values, metric definitions, and the bridge from "what the analysis says" to "what the business should do".
Built for the four DS rounds you cannot fail
SQL rounds — query-plan-aware hints
DS SQL rounds are not testing whether you can SELECT. They are testing whether you reach for the right window function, when to CTE, when to denormalise, and how a 50M-row query is going to scan. The copilot surfaces the canonical pattern (LAG, NTILE, FIRST_VALUE, anti-join, semi-join) the moment the question implies it.
A/B testing rounds — power, MDE, novelty
When the interviewer says "we shipped X, traffic moved Y%, what do you do?", the copilot scaffolds: was this powered for that effect, is the MDE plausible, are there novelty / Simpson / SUTVA issues, and what is the next experiment — not just "is p<0.05".
Metric-design rounds — north star, guardrail, proxy
Product DS interviews increasingly ask "define a metric for X". The copilot anchors the framework (north star + guardrails + proxies + counter-metrics), then evaluates trade-offs: lagging vs leading, gameable vs robust, dimensionality, normalisation, and the failure modes for each candidate metric.
Analytical case studies with business framing
The pattern that loses most DS interviews: candidate dives into the analysis without restating the business context. The copilot enforces the frame — what is the business question, what decision does this enable, what is the cost of being wrong — then walks the actual analysis underneath.
ML fundamentals on demand
Bias-variance, regularisation, evaluation metrics for imbalanced data, leakage detection, feature engineering, cross-validation strategy. The copilot has scaffolds for the 15 most-asked ML conceptual questions, calibrated to the interview level (junior DS vs senior DS vs ML-leaning DS).
Stakeholder communication prompts
DS interviews often end with "explain this to a non-technical PM". The copilot has tested phrasing patterns — anchor the business question, state the finding in one line, name the uncertainty, recommend the action — that consistently land with non-DS interviewers.
