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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 1–15 of 15 results

  • AmazonHardData Scientist
    Validate DID and IV assumptions rigorously

    This question evaluates mastery of causal inference and applied econometrics, specifically difference-in-differences, two-way fixed effects, staggered adoption and treatment heterogeneity, instrumental variables (2SLS), clustering, and GMM-based inference.

    Statistics & MathHR Screen
  • Capital OneEasyData Scientist
    Calculate Annual Profit of Credit Card Portfolio

    Evaluates annual profit calculation for a credit-card portfolio with monthly and annual revenue and cost components. Strong answers annualize figures, compute per-card profit, and scale to portfolio profit.

    Statistics & MathHR Screen
  • Capital OneEasyData Scientist
    Calculate Incremental Customers for Marketing Spend Justification

    Evaluates incremental customer calculations for partnership marketing spend justification. Strong answers derive break-even customers for fixed spend and required volume for variable-cost campaigns against a profit target.

    Statistics & MathHR Screen
  • Capital OneEasyData Scientist
    Differentiate fixed and variable costs with examples

    This question evaluates understanding of cost classification and unit economics—specifically the distinction between fixed and variable costs—and the competency to apply those concepts within a subscription streaming business context.

    Statistics & MathHR Screen
  • Capital OneEasyData Scientist
    Graph WTP vs content and explain cap

    This question evaluates understanding of piecewise linear functions, marginal analysis, and the economic interpretation of willingness-to-pay, within the Statistics & Math domain for a Data Scientist role.

    Statistics & MathHR Screen
  • Capital OneMediumData Scientist
    Set membership fee under investment constraints

    This question evaluates quantitative skills in pricing optimization, constrained investment allocation, and interpretation of willingness-to-pay curves, testing competency in combining economic reasoning with statistical and mathematical modeling.

    Statistics & MathHR Screen
  • CoinbaseMediumData Scientist
    Optimize no-penalty test strategy

    This problem tests your ability to model expected value under time constraints by balancing the probability of success per question against a limited resource pool.

    Statistics & MathHR ScreenProbabilityExpected ValueOptimization
  • GoogleEasyData Scientist
    Estimate weather’s effect on mental health

    This problem tests the ability to design an observational study to measure the causal impact of meteorological variables on self-reported mental health scores, focusing on confounding variables and identification strategies.

    Statistics & MathHR ScreenCausal InferenceRegressionConfounding
  • J.P. MorganMediumData Scientist
    Interpret Model Metrics, Regularization, and Resampling Fundamentals

    This problem tests your understanding of foundational machine learning metrics for imbalanced classification and the theoretical utility of regularization and resampling techniques.

    Statistics & MathHR ScreenStatisticsMachine LearningRegularization
  • MetaMediumData Scientist
    Analyze ad targeting expectations and distributions

    This question evaluates a data scientist's competency in probabilistic modeling, expected-value decision-making, variance decomposition for mixture distributions, and Poisson/exponential arrival-process analysis within the Statistics & Math domain.

    Statistics & MathHR Screen
  • Morgan StanleyMediumData Scientist
    Solve Market-Risk and Probability Questions

    Morgan Stanley data-scientist HR-screen quant set covering four sub-questions: design a WTI/Brent crude stress-testing framework using heavy-tailed marginals and a t-copula for joint tail dependence; the variance of a sum of correlated normal variables and when the sum is normal; the Monty Hall switching probability; and the eight-balls one-heavier puzzle in two weighings. It probes both conceptual understanding and practical application of dependence modeling, scenario generation, and probabilistic reasoning.

    Statistics & MathHR Screen
  • SamsungMediumData Scientist
    Estimate laptops in an office

    This question evaluates back-of-the-envelope estimation skills, quantitative reasoning, and the ability to state and justify assumptions when modeling real-world counts like devices.

    Statistics & MathHR Screen
  • TikTokMediumData Scientist
    Compute cluster-aware significance and sequential corrections

    This question evaluates competency in clustered randomized experiment analysis, including calculation of design effect and effective sample size, cluster-robust inference for differences in proportions, sequential alpha spending (O’Brien–Fleming-style) and comparisons with Bonferroni, Holm–Bonferroni adjustments for multiple guardrail metrics, and Bayesian ROPE interpretation. It is in the Statistics & Math domain and is commonly asked to probe how candidates handle intra-cluster correlation, control Type I error across interim looks and multiple metrics, and demonstrate both conceptual understanding and practical application of power, duration, and multiplicity trade-offs.

    Statistics & MathHR Screen
  • UpstartEasyData Scientist
    Determine distribution of aX+b when X~N(0,1)

    This problem tests your understanding of how linear (affine) transformations affect the properties of a normal distribution and the derivation of its mean and variance.

    Statistics & MathHR ScreenStatisticsProbabilityNormal Distribution
  • UpstartEasyData Scientist
    Identify binomial model and compute moments

    This question tests the ability to identify a binomial process, express its probability mass function, and derive its fundamental moments (mean and variance).

    Statistics & MathHR ScreenStatisticsProbabilityBinomial Distribution