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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 121–150 of 513 results

  • ConfluentMediumData Scientist
    Evaluate Metrics and Randomization for Onboarding Tutorial Change

    Evaluate Metrics and Randomization for Onboarding Tutorial Change 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
  • CoupangMediumData Scientist
    Reserving an Elevator for Food Deliveries

    This question evaluates your ability to design an A/B test for an operational policy change in a high-traffic environment, focusing on cluster randomization, metric selection, and handling network effects.

    Analytics & ExperimentationTechnical ScreenA/B TestingExperiment DesignMetrics
  • DiscordMediumData Scientist
    Design Product Notification and Autocomplete Experiments

    This question evaluates experimental design, causal inference, metric definition, selection bias analysis, logging and privacy considerations, and product analytics competencies for a data scientist working in Analytics & Experimentation.

    Analytics & ExperimentationTechnical Screen
  • DiscordMediumData Scientist
    Evaluate Model-Targeted Subscription Notifications

    Evaluate subscription-targeting notifications with incrementality metrics, A/A preparation, flat-result diagnosis, and alternative causal designs.

    Analytics & ExperimentationTechnical Screen
  • DisneyHardData Scientist
    Diagnose and decide on watch-time drop

    This question evaluates a data scientist's skills in causal inference, experiment analytics, metric definition and guardrails, confounder adjustment, and rapid decision-making under time pressure.

    Analytics & ExperimentationHR Screen
  • DoorDashHardData Scientist
    Assess Success Criteria for Bike-Courier Delivery Launch

    Evaluates marketplace analytics for launching a bike-courier delivery option in dense delivery markets. Strong answers define stakeholder value, success metrics, market selection, phased rollout, guardrails, and causal evaluation under network effects.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Boost App Installs: Analyze and Experiment with Conversion Funnel

    DoorDash analytics prompt on improving mobile web to app-install conversion, covering funnel measurement, attribution, cohorts, install and activation experiments, incentives, guardrails, and long-term retention impact.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Decide and test a 20% discount strategy

    This question tests the ability to design a controlled experiment to evaluate a promotional discount strategy, focusing on causality, profit optimization, and long-term customer value impact.

    Analytics & ExperimentationOnsiteCausal InferenceExperimentationUplift Modeling
  • DoorDashHardData Scientist
    Decompose and optimize delivery operational costs

    This question evaluates a data scientist's ability to decompose per-order operational costs, identify high-impact levers to reduce unit economics, and design rigorous experiments and monitoring for a two-sided delivery marketplace, testing competencies in cost modeling, causal inference, experimentation design, and product analytics.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Define metrics for new market expansion success

    This question tests the ability to design a comprehensive evaluation framework for entering a new geographic market by balancing growth, unit economics, and marketplace balance.

    Analytics & ExperimentationOnsiteAnalyticsMarketplaceKPIs
  • DoorDashMediumData Scientist
    Design Biker metrics and A/B test plan

    This question tests the ability to design an experimentation framework for a two-sided marketplace, focusing on metric definition, causal inference, and identifying potential gaming behaviors in delivery logistics.

    Analytics & ExperimentationTechnical ScreenA/B TestingMarketplace AnalyticsMetric Design
  • DoorDashMediumData Scientist
    Design Experiments to Measure Promotion Scheduling Impact

    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 Design Experiments to Measure Promotion Scheduling Impact states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • DoorDashEasyData Scientist
    Design a Top Dasher experiment with interference

    This problem tests your ability to design a controlled experiment in a marketplace with network effects, specifically focusing on how to mitigate spillover interference between treated and control groups.

    Analytics & ExperimentationOnsiteExperimentationCausal InferenceMarketplace
  • DoorDashHardData Scientist
    Design an experiment for order batching

    This question evaluates competence in experiment design and causal inference for marketplace interventions, covering choice of randomization unit and mitigation of interference/spillovers, stratification and covariate adjustment, power and sample‑size calculations, detection of novelty/steady‑state effects, heterogeneity estimation, and pre-registered guardrail decision rules. It is commonly asked in the Analytics & Experimentation domain because interviewers need to assess both conceptual understanding of causal inference and the practical application of randomized designs and operational measurement to ensure robust, contamination‑aware evaluation of policy changes.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Design analysis to reduce cold-delivery complaints

    This problem tests the ability to diagnose a service quality issue, define key performance indicators, and design an experiment to evaluate an operational intervention while controlling for confounding variables.

    Analytics & ExperimentationTechnical ScreenCausal InferenceExperimental DesignProduct Metrics
  • DoorDashMediumData Scientist
    Design and Evaluate a Refund Policy for Delayed Orders

    Design an automated, data-driven compensation policy for late deliveries on a three-sided marketplace. Formulate delay thresholds, balance customer lifetime value against operational costs, and structure an A/B test with appropriate randomization and guardrail metrics.

    Analytics & ExperimentationOnsiteexperimentationab-testingmarketplace-analytics
  • DoorDashHardData Scientist
    Design and analyze a switchback experiment

    This question evaluates proficiency in experimental design, causal inference, randomization and contamination control, regression modeling with fixed effects and clustered standard errors, power calculation, and handling of compliance and robustness issues.

    Analytics & ExperimentationTechnical Screen
  • DoorDashHardData Scientist
    Design and analyze batching algorithm experiment

    This problem tests the ability to design a cluster-randomized experiment in a marketplace setting, focusing on managing network effects (spillover) and defining appropriate inference strategies for geo-based batches.

    Analytics & ExperimentationOnsiteExperimentationCausal InferenceMarketplace
  • DoorDashHardData Scientist
    Design experiments for marketplace product changes

    This question evaluates experiment design, causal inference, product-analytics, and metric-definition skills for multi-sided marketplaces, focusing on handling interference, spillovers, heterogeneity, and trade-offs between conversion, retention, credit burn, and monetization.

    Analytics & ExperimentationOnsite
  • DoorDashEasyData Scientist
    Design experiments for payments, search, and promotions

    This question tests your ability to design robust A/B tests for marketplace products, focusing on metric selection, identifying interference, and accounting for ecosystem-level trade-offs.

    Analytics & ExperimentationOnsiteA/B TestingMarketplace AnalyticsCausal Inference
  • DoorDashMediumData Scientist
    Determine Success Metrics for Biker Dasher Program Launch

    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 Success Metrics for Biker Dasher Program Launch states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Diagnose Cold Food Deliveries with Key Metrics Analysis

    DoorDash analytics prompt on diagnosing cold food deliveries, covering complaint metrics, lifecycle timestamps, batching, packaging, weather, segmentation, data quality, A/B testing, and operational guardrails.

    Analytics & ExperimentationOnsite
  • DoorDashMediumData Scientist
    Diagnose Cold-Food Deliveries and Make a Launch Decision

    Work through a product analytics case about diagnosing a delivery-quality problem and deciding whether an intervention should launch. The question tests metric hierarchy, causal reasoning, investigation design, power considerations, and decision criteria.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Diagnose Decline in Successful Orders

    This question evaluates a data scientist's skills in marketplace analytics, causal reasoning, metric framework design, and experimentation for diagnosing a decline in successful orders.

    Analytics & ExperimentationTechnical Screen
  • DoorDashHardData Scientist
    Diagnose LA completed-order drop and design experiment

    This question evaluates a data scientist's competency in funnel-based diagnostics, causal inference, and experimental design for distinguishing supply-side versus demand-side drivers in a two-sided marketplace, emphasizing metric selection, segmentation, and guardrail monitoring.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Diagnose Why Delivered Food Arrives Cold

    Investigate an increase in cold food complaints by decomposing fulfillment timestamps, evaluating mix shifts versus operational degradation, and designing a mitigation experiment with balanced marketplace guardrails.

    Analytics & ExperimentationOnsiteanalyticsexperimentationfunnel-analysis
  • DoorDashMediumData Scientist
    Diagnose a Decline in Order Acceptance Rate

    Evaluate a sudden drop in Dasher order acceptance rate by verifying data integrity, decomposing segment-level shifts, and designing an experiment to mitigate downstream marketplace impacts.

    Analytics & ExperimentationOnsiteProduct AnalyticsMetric DecompositionA/B Testing
  • DoorDashMediumData Scientist
    Diagnose a One-Day Drop in Successful Deliveries

    Tests the candidate's structured metric troubleshooting, funnel decomposition, and root cause analysis for an acute drop in core marketplace volume. Evaluates the ability to separate count effects from conversion rate changes and isolate partner-specific vs. market-wide anomalies.

    Analytics & ExperimentationTechnical Screenmetric-troubleshootingfunnel-analysismarketplace-analytics
  • DoorDashHardData Scientist
    Diagnose and experiment to reduce late deliveries

    This question evaluates a data scientist's competencies in causal inference, metrics engineering, data instrumentation and joining, root‑cause analysis, and experiment design focused on operational delivery performance.

    Analytics & ExperimentationTechnical Screen
  • DoorDashHardData Scientist
    Diagnose and reduce cold-food refund costs

    This problem tests the ability to diagnose root causes of operational cost drivers and design a rigorous experiment to validate potential mitigation policies.

    Analytics & ExperimentationTechnical ScreenCausal InferenceExperimentationMarketplace Analytics