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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.
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Showing 211–240 of 513 results
- HuluMediumData ScientistDesign and Monitor a Multi-Country Parameter Experiment
This question tests the ability to design an A/B test across multiple regions while accounting for sample size requirements, variance reduction techniques, and sequential monitoring protocols.
Analytics & ExperimentationTechnical ScreenA/B TestingPower AnalysisCUPED - HuluMediumData ScientistInterpret a Streaming Regression Without Overstating Causality
This problem tests your ability to interpret multivariate regression results for product stakeholders, specifically focusing on distinguishing correlation from causation and identifying risks like collider bias.
Analytics & ExperimentationTechnical ScreenRegressionCausal InferenceExperimental Design - IBMEasyData ScientistEstimate free-trial conversion probability
This question evaluates a data scientist's competency in cohort definition, censored-data handling, segmentation and confounding assessment, and uncertainty quantification for measuring free-trial to paid conversion, and it belongs to the Analytics & Experimentation domain within data science.
Analytics & ExperimentationTechnical Screen - InstacartHardData ScientistAnalyze A/B test with revenue–cost tradeoffs
This question evaluates a data scientist's skills in experimental design and statistical inference for A/B testing, revenue-impact modeling with skewed and zero-inflated metrics, segmentation for heterogeneous treatment effects, and constrained optimization to balance contribution and operational risk.
Analytics & ExperimentationOnsite - InstacartHardData ScientistCompute duration and stopping rules correctly
This question evaluates a data scientist's competency in experimental design and applied statistics, specifically power and sample‑size calculations, accounting for intra‑household clustering and design effects, sequential monitoring for peeking control, and variance‑reduction or stratified randomization to handle day‑of‑week seasonality.
Analytics & ExperimentationOnsite - InstacartEasyData ScientistDesign a pricing experiment with network effects
This question evaluates experimental design and causal inference competencies for a two-sided marketplace pricing change, including handling network effects/interference, choice of unit of randomization and treatment markets, metric selection and diagnostics, power/MDE estimation, and operational risk assessment within the Analytics & Experimentation domain for a Data Scientist role. It is commonly asked to assess practical application of randomized and quasi-experimental methods across heterogeneous geographies and operational constraints, requiring both hands-on experimental design skills and conceptual understanding of bias, spillovers, and diagnostic metrics.
Analytics & ExperimentationTechnical Screen - InstacartHardData ScientistDesign and Interpret an A/B Test
This question tests the ability to design a statistically rigorous A/B test, calculate sample sizes based on effect thresholds, and account for real-world constraints like seasonality and multiple comparisons.
Analytics & ExperimentationOnsiteA/B TestingPower AnalysisStatistics - InstacartMediumData ScientistDiagnose and fix low conversion rigorously
This question evaluates a Data Scientist's competency in analytics and experimentation, covering instrumentation validation, funnel and segmentation analysis, causal inference methods (holdouts/DiD), system reliability diagnostics, statistical power and sample-size estimation, and the ability to synthesize findings into executive-level impact statements. It is commonly asked to determine whether a candidate can distinguish measurement or product regressions from marketing-mix shifts and to demonstrate both conceptual understanding of causal inference and practical application of data querying, metric definition, and experiment design in the Analytics & Experimentation domain.
Analytics & ExperimentationHR Screen - InstacartEasyData ScientistHow to debug an apparent D14 retention drop
This question evaluates competency in cohort-based retention analysis, understanding metric maturity and right-censoring, performing data quality and definition checks, and localizing real declines across segments, releases, or funnel changes.
Analytics & ExperimentationTechnical Screen - InstacartEasyData ScientistHow would you investigate a metric decline?
This question evaluates a data scientist's competency in diagnostic analytics, metric instrumentation awareness, causal reasoning, and segmentation-driven problem localization for consumer marketplace KPIs.
Analytics & ExperimentationTechnical Screen - InstacartMediumData ScientistInvestigate Instacart Revenue Decline Using Weekly Data
Instacart analytics prompt on investigating a 4% weekly revenue decline, covering time-series anomaly detection, seasonality, changepoints, prediction intervals, and richer-data decomposition by orders, AOV, geography, cohorts, and categories.
Analytics & ExperimentationTechnical Screen - InstacartEasyData ScientistInvestigate marketplace metrics and experiment rollout
This question evaluates competency in marketplace analytics, causal inference, experimentation design, metric instrumentation, cohort and retention analysis, and trade-off reasoning between core business metrics and secondary signals.
Analytics & ExperimentationTechnical Screen - InstacartMediumData ScientistRecommend and validate a budget allocation strategy
This question evaluates a data scientist's competency in budget allocation, experimental design, KPI definition, segmentation, and causal inference by requiring translation of SQL-derived spend and profitability insights into constrained program- and advertiser-level budget rules while managing concentration risk.
Analytics & ExperimentationTechnical Screen - IntuitMediumData ScientistBuild 30-day retention cohort table
This problem tests your ability to aggregate user activity data to calculate 30-day retention rates, requiring joins, date arithmetic, and windowing functions.
Analytics & ExperimentationTechnical ScreenSQLRetentionCohort Analysis - IntuitMediumData ScientistBuild cohort 30-day retention from signup date
This problem tests your ability to manipulate time-series data to calculate cohort-based user retention rates while handling data censoring constraints.
Analytics & ExperimentationTechnical ScreenSQLPandasRetention - IntuitEasyData ScientistDesign an experiment for pricing page redesign
This question evaluates a candidate's competency in experiment design, causal inference, impact sizing, metric framework development, and statistical analysis in the context of a pricing page redesign that adds an annual subscription option.
Analytics & ExperimentationTechnical Screen - LinkedInHardData ScientistAnalyze homepage drop and feed ranking
This question evaluates a candidate's competency in product analytics, causal diagnosis, instrumentation and logging validation, segmentation and cohort analysis, and experimental design for feed ranking and user-path behavior.
Analytics & ExperimentationTechnical Screen - LinkedInHardData ScientistDesign Experiments for Email Campaign & Messaging Update
Evaluates experiment design for concurrent email and in-product messaging launches with possible interaction effects. Strong answers use factorial designs, power calculations, interaction terms, sequential testing, and guardrails.
Analytics & ExperimentationOnsite - LinkedInMediumData ScientistDiagnose a Drop in Applications from Job Recommendation Emails
Diagnose falling applications from job emails by tracing funnel rates, recommendation relevance, promoted-job mix, and ranking changes.
Analytics & ExperimentationOnsite - LinkedInEasyData ScientistDo US members upload more videos than non-US?
This question evaluates a data scientist's competency in analytics and experimentation, specifically metric design, confounder control, cohorting, and statistical inference for comparing user behavior across segments.
Analytics & ExperimentationTechnical Screen - LinkedInMediumData ScientistEstimate Redesign Impact Using Propensity Score Matching
Estimate Redesign Impact Using Propensity Score Matching evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite - LinkedInMediumData ScientistHow to analyze Simpson's paradox
This question evaluates competency in causal reasoning, statistical inference, experimental design, and detection of Simpson's paradox within the Analytics & Experimentation domain.
Analytics & ExperimentationTechnical Screen - LinkedInHardData ScientistHow to diagnose traffic and measure relevance?
This problem tests your ability to diagnose an unexplained drop in engagement metrics by decomposing a complex user funnel, isolating root causes using multidimensional data, and designing a robust validation framework.
Analytics & ExperimentationTechnical ScreenRoot Cause AnalysisMetrics StrategyFunnel Analysis - LinkedInMediumData ScientistImprove Profile Completion Rate
Evaluates analytics and experimentation strategy for improving LinkedIn profile completion. Strong answers define value-weighted completion metrics, segment gaps, prioritize interventions, and test impact with guardrails.
Analytics & ExperimentationOnsite - LinkedInHardData ScientistMeasure Relevant Feed Success
This question tests the ability to define North Star metrics for a social feed and design an experimentation framework that accounts for long-term ecosystem health and cross-side network effects.
Analytics & ExperimentationTechnical ScreenProduct AnalyticsA/B TestingMetrics - LinkedInMediumData ScientistMeasure Success of New B2B Product
Evaluates success measurement for a new LinkedIn B2B SaaS product at account and seat levels. Strong answers define activation, engagement, value, retention, expansion, anomaly analysis, and growth prioritization.
Analytics & ExperimentationOnsite - LinkedInMediumData ScientistPresent Insights from Course Supply and Participation Data
Analyze course catalog supply and learner participation using time trends, category comparisons, utilization measures, and evidence-based presentation.
Analytics & ExperimentationOnsite - LinkedInMediumData ScientistResolve Conflicting A/B Test Results in Cities
Evaluates interpretation of conflicting A/B test results across cities using Simpson's paradox and stratified estimands. Strong answers check weighting, SRM, heterogeneity, confidence intervals, and rollout criteria.
Analytics & ExperimentationTechnical Screen - LinkedInEasyData ScientistResolve Simpson’s paradox in A/B email test
This question tests your ability to identify and resolve Simpson's Paradox in A/B test results, where an aggregate trend disappears or reverses when segmented by user cohorts.
Analytics & ExperimentationTechnical ScreenA/B TestingSimpson's ParadoxConfounding - LinkedInMediumData ScientistSingle Queue vs Multiple Queues — Service Design
Evaluates queueing-system reasoning for single-line versus multiple-line bank teller designs. Strong answers compare M/M/c pooling with parallel M/M/1 queues, waiting-time averages, variance, stability, fairness, and operations.
Analytics & ExperimentationOnsite