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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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Calculate 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 Scientist
    Characterize 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 Scientist
    Characterize 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 Scientist
    Choose 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 Scientist
    Choose 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 Scientist
    Choose 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 Scientist
    Choose 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 Scientist
    Clarify 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 Scientist
    Communicate 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 Scientist
    Compare 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 Scientist
    Compare 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 Scientist
    Compare 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 Scientist
    Compare 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 Scientist
    Compare 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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 Scientist
    Compute 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