Lead/Senior Data Scientist Interview Playbook

Most data science interview prep is built for entry-level candidates: LeetCode-style questions and flashcard-style ML trivia. Almost none of it addresses what actually gets asked at the lead or senior level, where the questions shift from "do you know this algorithm" to "can you scope an ambiguous problem, defend a tradeoff to a skeptical VP, and design a system end to end."

This template is built around that gap.

What's inside:

• Module 0: Orientation: what actually changes at the lead/senior level, and what interviewers are screening for that they never say out loud
• Module 1: Stats & Probability: experiment design, causal inference, and the traps that show up in senior interviews (Simpson's paradox, sample ratio mismatch, peeking problems), not just formula recall
• Module 2: ML Fundamentals & Algorithms: model selection, evaluation metrics, cross-validation strategy, and interpretability, framed around real judgment calls
• Module 3: Deep Learning: when deep learning is (and isn't) the right tool, attention mechanisms explained simply, and the tradeoffs that come up in real system design
• Module 4: Python & SQL: production-grade code and query design, not algorithm-trivia questions
• Module 5: ML System Design: 4 full worked case studies (retail demand forecasting, fraud detection, CPG recommendations, pharma churn), each walked through a clarify → data → features → model → evaluation → deployment framework
• Module 6: Business & Leadership Cases: STAR-format story prep, behavioral prompts, and industry-flavored scenario questions pulled from retail, CPG, and pharma dynamics
• Module 7: Self-Assessment Quizzes: 14 click-to-reveal Q&A pairs across stats, ML, deep learning, and Python/SQL, so you can actually test retention instead of just re-reading notes

The Confidence Tracker: a built-in Notion database that color-codes your self-rated confidence per topic (red/yellow/green) and automatically sorts your weakest areas to the top every time you open it, so you always know exactly what to study next.

Format: Notion template, delivered as a duplicate link. Works on the free Notion plan. Everything duplicates directly into your own workspace, fully editable.

This isn't a static PDF of questions. It's a living study system: fill in your own notes, add your own case study answers, rate your confidence as you go, and watch the tracker tell you where to focus next.

Built by a seasoned data scientist with 10+ years of experience working in Retail, CPG, and Pharma industries.