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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 1081–1110 of 1971 results

  • MetaHardData Scientist
    Design experiment for Group Calls with interference

    This question evaluates a data scientist's competency in experimental design and causal inference for networked features, covering metrics selection (primary and guardrail metrics), strategies for mitigating interference via randomization or quasi-experimental approaches, exposure and contamination controls, rollout planning, and pre-registration and power analysis. Commonly asked in Analytics & Experimentation interviews for Data Scientist roles, it assesses reasoning about bias–variance trade-offs, engineering constraints, and validity diagnostics in interconnected user environments, requiring both conceptual understanding of identification and practical application of experiment implementation.

    Analytics & ExperimentationTechnical Screen
  • MetaHardData Scientist
    Design experiments under network interference

    This question evaluates a data scientist's competence in experimental design and causal inference under network interference, assessing understanding of clustering strategies, exposure and exclusion definitions, contamination control, design effect and sample-size implications, estimation of intra-cluster correlation, and mixed-effects analysis for evolving clusters. Commonly asked in Analytics & Experimentation interviews to probe the ability to preserve internal validity while managing operational feasibility in two-sided marketplaces, it tests both conceptual understanding of interference and practical application skills in design and analysis planning.

    Analytics & ExperimentationOnsite
  • MetaMediumData Scientist
    Design marketplace experiments at DoorDash

    This question evaluates a candidate's skills in experimental design, product and marketplace analytics, causal inference, and diagnostic data science for multi-sided platforms.

    Analytics & ExperimentationTechnical Screen
  • MetaHardData Scientist
    Design metrics for violating content exposure

    This question evaluates competency in metric design and measurement for content safety, including defining exposure metrics, inclusion/exclusion rules, handling label latency and appeals, uncertainty-aware alerting, and A/B test design for a Data Scientist role in the Analytics & Experimentation domain.

    Analytics & ExperimentationTechnical Screen
  • MetaEasyData Scientist
    Design metrics to detect harmful content and fraud

    This problem tests the ability to design robust monitoring metrics for detecting fraudulent user activity and policy-violating content, focusing on trade-offs between precision and recall.

    Analytics & ExperimentationOnsiteAnalyticsMetricsFraud-Detection
  • MetaMediumData Scientist
    Design pre-launch plan and cluster A/B test

    This question evaluates a candidate's skills in experimental design, causal inference, cluster randomization, metric definition and instrumentation, power analysis, and phased rollout decision-making.

    Analytics & ExperimentationTechnical Screen
  • MetaMediumData Scientist
    Design robust group size limiting for calls

    This question evaluates distributed systems design, concurrency control, admission-control algorithms, and scalability under real-time and race-condition constraints.

    Coding & AlgorithmsTechnical Screen
  • MetaMediumData Scientist
    Design video-ads experiment and handle null results

    This question evaluates experimental design, causal inference, statistical power analysis, metric definition, and operational analytics competency within the Analytics & Experimentation domain for a Data Scientist role.

    Analytics & ExperimentationTechnical Screen
  • MetaMediumData Scientist
    Detect and address Simpson’s paradox

    This question evaluates understanding of aggregation bias and Simpson's paradox, proficiency with stratified or mixed-model estimators, heterogeneity testing, and experiment decisioning within Analytics & Experimentation for a Data Scientist role.

    Analytics & ExperimentationOnsite
  • MetaEasyData Scientist
    Detect bots using comment distribution patterns

    This problem tests your ability to define metrics for identifying automated behavior and your statistical intuition for validating those metrics against human behavior.

    Analytics & ExperimentationTechnical ScreenAnalyticsAnomaly DetectionFeature Engineering
  • MetaHardData Scientist
    Detect leakage and evaluate a prediction model

    This question evaluates competence in production-ready supervised machine learning—detecting and repairing data leakage in logs-based features, designing time-aware cross-validation, defining KPI-driven thresholding and calibration, interpreting model coefficients, and establishing monitoring and retraining policies for a churn prediction model in the Machine Learning domain. It is commonly asked because interviewers need to assess both conceptual understanding of leakage, validation, and calibration principles and practical application skills for deploying and maintaining models with cost-sensitive objectives and monitoring in production, so the level of abstraction spans conceptual reasoning and hands-on practical application.

    Machine LearningOnsite
  • MetaMediumData Scientist
    Determine High-Quality Notifications with CTR Analysis

    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 Determine High-Quality Notifications with CTR Analysis states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • MetaHardData Scientist
    Determine Key Metrics and Design A/B Test for Ad Ranking

    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 Determine Key Metrics and Design A/B Test for Ad Ranking states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • MetaMediumData Scientist
    Determine Metrics to Evaluate Notification Impact on Users

    Evaluates product analytics judgment for Facebook push notifications, including how to measure helpful versus harmful notifications, design an event-notification experiment, and balance short-term clicks against retention, fatigue, and opt-out guardrails. Strong answers build a metric hierarchy and use causal measurement.

    Analytics & ExperimentationOnsite
  • MetaMediumData Scientist
    Determine Old vs. New Users' Shop Visibility Changes

    This question evaluates SQL-focused data manipulation skills and analytical competency in cohort definition and metric selection for comparing behavioral propensities, specifically assessing how to measure the likelihood of old versus new users switching a shop profile to invisible.

    Data Manipulation (SQL/Python)Onsite
  • MetaEasyData Scientist
    Determine Posterior Probability of Bad User Prediction

    Meta Bayes theorem question on a bad-actor classifier, covering prevalence, sensitivity, specificity, false positives, positive predictive value, and the base-rate effect.

    Statistics & MathOnsite
  • MetaMediumData Scientist
    Determine Probability of Fourth Good Response After Three Successes

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Determine Probability of Fourth Good Response After Three Successes states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathOnsite
  • MetaEasyData Scientist
    Determine Probability of Friend Request Being Fake

    Determine Probability of Friend Request Being Fake 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
    Determine Unhealthy Oculus Usage with SQL Analysis

    This question evaluates SQL-based data manipulation and time-series analysis competencies, including sessionization, user-day aggregation, and detection of sustained behavioral patterns in event data; it is categorized under Data Manipulation (SQL/Python) and targets practical application skills.

    Data Manipulation (SQL/Python)Onsite
  • MetaMediumData Scientist
    Determine Value of Prioritizing Accounts by Unread Notifications

    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 Determine Value of Prioritizing Accounts by Unread Notifications states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • MetaHardData Scientist
    Determining the optimal ad load in News Feed

    Evaluates optimal News Feed ad-load strategy using marginal revenue, user tolerance, and long-term LTV. Strong answers test ad-load levels, segment tolerance, personalize caps, and monitor revenue, retention, and user-experience guardrails.

    Analytics & ExperimentationTechnical Screen
  • MetaHardData Scientist
    Diagnose sales correlations without claiming causality

    This question tests the ability to design an observational study that identifies associations between a new feature adoption and sales growth while strictly avoiding causal claims in the presence of self-selection bias.

    Analytics & ExperimentationTechnical ScreenObservational StudyCausal InferenceAnalytics
  • MetaMediumData Scientist
    Employ Collaborative Filtering for Personalized Recommendation Lists

    Meta machine learning prompt on collaborative filtering and personalized ranking, covering multi-stage recommenders, embeddings, learning-to-rank, role and context constraints, cold start, serving architecture, and evaluation.

    Machine LearningTechnical Screen
  • MetaMediumData Scientist
    Ensure Effective Teamwork Amid Conflicting Stakeholder Opinions

    This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Ensure Effective Teamwork Amid Conflicting Stakeholder Opinions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Behavioral & LeadershipOnsite
  • MetaHardData Scientist
    Estimate CTR lift with binomial tests and errors

    This question evaluates statistical inference for proportions, sequential monitoring, and multiple-comparison error control—assessing competence with binomial-based CTR comparison, pooled standard errors, z-tests and confidence intervals, Type I error inflation from peeking, and FWER/FDR considerations.

    Statistics & MathOnsite
  • MetaMediumData Scientist
    Estimate Lift and Significance in Facebook Ad Campaigns

    Meta statistics prompt on Facebook ad conversion lift, covering absolute and relative lift, two-proportion tests, confidence intervals, power for 5% relative lift, and Bayesian beta-binomial reframing.

    Statistics & MathOnsite
  • MetaMediumData Scientist
    Estimate Portal’s causal lift on video-call usage

    This problem tests the ability to design an observational causal inference framework using Difference-in-Differences (DiD) in a setting with staggered adoption, specifically addressing selection bias and household-level measurement errors.

    Statistics & MathTechnical ScreenCausal InferenceDifference-in-DifferencesStaggered Adoption
  • MetaHardData Scientist
    Estimate and validate weights for engagement actions

    This question tests the ability to derive an engagement scoring model, handle high-dimensional collinear features, and establish a robust validation framework for point-in-time predictions.

    Statistics & MathTechnical ScreenRegressionRegularizationMulticollinearity
  • MetaMediumData Scientist
    Estimate bots and CI from DAU spike

    This question tests the ability to decompose a mixture of legitimate user traffic and synthetic bot/CI traffic using statistical modeling, and requires justifying the choice of distribution for overdispersed count data.

    Statistics & MathOnsiteMixture ModelsNegative BinomialBootstrapping
  • MetaMediumData Scientist
    Estimate fake-account prevalence with capture-recapture

    This question tests the ability to apply the Lincoln-Petersen estimator to estimate a hidden population size and addresses the limitations of the assumptions underlying capture-recapture methods.

    Statistics & MathOnsiteStatisticsEstimationInference