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Data Scientist Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
- Questions
- 546
- Companies
- 11
- Topics
- 8
- Languages
Showing 991–1020 of 1971 results
- MetaMediumData ScientistCalculate French User Engagement and U.S. Call Duration
This question evaluates proficiency in SQL-based data manipulation and analytics, testing skills such as joining event and profile tables, aggregating metrics, and computing user-level engagement proportions and average durations.
Data Manipulation (SQL/Python)Technical Screen - MetaEasyData ScientistCalculate Posterior Fraud Probability Using Bayes' Theorem
Calculate Posterior Fraud Probability Using Bayes' Theorem evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - MetaEasyData ScientistCalculate Posterior Probability of Flagged User Being Bad Actor
Evaluates Bayesian inference and confusion-matrix reasoning for abuse detection. Strong answers derive posterior precision from prevalence, TPR, and FPR, define Type I and Type II errors, and compute true positives and false positives for 10 million users.
Statistics & MathOnsite - MetaEasyData ScientistCalculate Probability of Honest and Relevant Chatbot Answers
Calculate Probability of Honest and Relevant Chatbot Answers evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - MetaMediumData ScientistCalculate Survey Response Rate and Quality Metric in SQL
This question evaluates SQL data-manipulation competencies such as aggregation, NULL handling, deduplication (first-per-group), and computing engagement and quality metrics from event logs.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCalculate Total Revenue in USD Using SQL Query
This question evaluates proficiency in SQL data manipulation, focusing on joins, aggregations, and handling currency conversion across relational tables.
Data Manipulation (SQL/Python)Onsite - MetaMediumData ScientistCalculate Video Call Usage Metrics by Country and Date
This question evaluates data manipulation and product-analytics skills, focusing on joining user and call datasets, aggregations for distinct-user percentages, and per-DAU duration calculations.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCalculate and Compare Survey Response Rates for User Tenure
This question evaluates proficiency in relational data manipulation and metric computation, including SQL joins, aggregation and cohort-based comparisons relevant to survey response analysis, and is categorized under Data Manipulation (SQL/Python) for a Data Scientist role.
Data Manipulation (SQL/Python)Onsite - MetaMediumData ScientistCharacterize and compare transfer-count distributions over time
This question evaluates a candidate's ability to model zero-inflated, heavy-tailed count data, interpret distributional summaries and percentiles, reason about temporal shifts from retention and fraud dynamics, and identify robust summary statistics and diagnostics for a Data Scientist role.
Statistics & MathOnsite - MetaMediumData ScientistCharacterize metric distribution and quantiles
This question evaluates a data scientist's competency in descriptive statistics and robust metric analysis within the Statistics & Math domain, focusing on distribution characterization, empirical quantiles, measures of central tendency, and the effects of outlier handling on variance and experimental power.
Statistics & MathOnsite - MetaHardData ScientistChoose alternatives when randomization fails
This question evaluates proficiency in causal inference and experimentation analytics for a Data Scientist role, focusing on selecting appropriate identification strategies, designing placebo and pre‑trend tests, and specifying robustness and sensitivity analyses for non‑randomized feature adoption.
Analytics & ExperimentationOnsite - MetaHardData ScientistChoose and compute recommender evaluation metrics
This question evaluates competency in offline recommender-system evaluation, propensity-weighted policy comparison, classification metric interpretation, probability calibration, model selection trade-offs, and handling data leakage and network interference.
Machine LearningHR Screen - MetaHardData ScientistChoose group-call size cap via experiment
This question evaluates a candidate's competency in experimental design, A/B testing and statistical analysis for product decisions, specifically testing metric selection, reliability and latency guardrails, stratified randomization, interference and clustering effects, heterogeneity detection, and operational stopping rules.
Analytics & ExperimentationTechnical Screen - MetaMediumData ScientistChoose threshold under asymmetric costs
This question evaluates cost-sensitive classification, operating-threshold selection, score calibration, drift monitoring, and experiment and guardrail design competencies within the Machine Learning domain.
Machine LearningOnsite - MetaHardData ScientistClarify scope and align to mission
This question evaluates a data scientist's product sense, leadership and stakeholder-alignment skills, including scope clarification, mission translation, metric definition, and collaborative communication.
Behavioral & LeadershipTechnical Screen - MetaHardData ScientistCommunicate trade-offs and influence launch
This question evaluates product judgment, experimentation interpretation, and cross-functional leadership skills for a data scientist, focusing on communicating trade-offs between per-account metric lifts and cross-account cannibalization; Category: Behavioral & Leadership, Domain: data science and product experimentation.
Behavioral & LeadershipTechnical Screen - MetaEasyData ScientistCompare Ad-Insertion Strategies: Expected Ads and Probabilities
Evaluates probability, expectation, and variance for newsfeed ad-insertion strategies. Strong answers compute expected ad load, at-least-one exposure probability, and explain why equal expected counts can still produce different user experiences.
Statistics & MathOnsite - MetaMediumData ScientistCompare Bayesian and frequentist decisions
This question evaluates understanding of Bayesian inference versus frequentist hypothesis testing, decision theory under asymmetric loss, sequential monitoring/optional stopping, and prior elicitation applied to A/B testing within the Statistics & Math domain.
Statistics & MathOnsite - MetaMediumData ScientistCompare Instagram and Facebook Stories Using Key Performance Metrics
This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Compare Instagram and Facebook Stories Using Key Performance Metrics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite - MetaMediumData ScientistCompare Instagram vs. Facebook using causal experiments
This question evaluates causal inference, experimentation design, metric engineering, and ecosystem-level impact assessment skills for a Data Scientist in the Analytics & Experimentation domain, with emphasis on defining a single-objective OEC that prevents pure cannibalization and on measuring cross-app effects via randomized rollouts.
Analytics & ExperimentationOnsite - MetaMediumData ScientistCompare Survey Satisfaction for New and Established Users
Tests your ability to write PostgreSQL queries that segment users into cohorts based on date logic, filter invalid survey events, and calculate aggregate satisfaction metrics.
Data Manipulation (SQL/Python)Technical Screensqlpostgresqldata-aggregation - MetaMediumData ScientistCompute 7-day views and reactions by relationship
This question evaluates skills in SQL-based data manipulation—specifically deduplication by longest duration, join-based attribution of reactions to views, window functions, distinct counts, aggregations, and date-range filtering within the Data Manipulation (SQL/Python) domain.
Data Manipulation (SQL/Python)Technical Screen - MetaEasyData ScientistCompute Bayes probability for fake accounts
This question tests the ability to apply Bayes' Theorem in a practical classification scenario, specifically accounting for low base-rate bias and conditional probabilities.
Statistics & MathOnsiteBayes TheoremProbabilityStatistics - MetaMediumData ScientistCompute CTR overall and by campaign type
This question evaluates data manipulation and analytics skills, specifically SQL aggregations, deduplication of event logs, time-window filtering, joins to campaign metadata, and safe ratio computation including division-by-zero handling.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute Each Advertiser's Share of Shop Ad Spend
This problem tests your ability to perform windowed aggregations, conditional filtering, and percentage calculations across multiple tables using SQL.
Data Manipulation (SQL/Python)OnsiteSQLAggregationWindow Functions - MetaHardData ScientistCompute High-Call Usage Rates
This question evaluates a candidate's ability to perform advanced data manipulation and analytical SQL tasks, including joins, aggregations, timezone-aware date handling, rolling window metrics, distinct user counting, and counting user participations across roles.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute SHOP spend share and model performance
This question evaluates proficiency in SQL/Python data manipulation and analytics, focusing on aggregations, joins, time-window computations, handling missing or zero values, and deriving key metrics such as revenue share and revenue-per-conversion.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute Shop Visibility Rate Using SQL and Python
This question evaluates proficiency in data manipulation and metric design using SQL and Python, focusing on event-level aggregation, user deduplication, and definition of a business visibility metric within the Data Manipulation (SQL/Python) domain.
Data Manipulation (SQL/Python)Onsite - MetaEasyData ScientistCompute active ad revenue by creation source
This question evaluates proficiency in data manipulation and analytics, testing skills such as joining event and impression tables, aggregating time-series revenue, and counting distinct active ads broken down by creation source.
Data Manipulation (SQL/Python)Onsite - MetaMediumData ScientistCompute ad impression conversion rates
This question evaluates proficiency in time-based event attribution, aggregation of business metrics (impressions, conversion rates, spend and revenue), timestamp handling, and user/ad-level matching within the Data Manipulation (SQL/Python) domain, emphasizing practical application over abstract theory.
Data Manipulation (SQL/Python)Onsite