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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 451–480 of 513 results

  • TikTokMediumData Scientist
    Analyze promo anomaly and design risk guardrails

    This question evaluates a candidate's ability to diagnose promotional anomalies, distinguish coordinated abuse from organic virality, design real-time approve/hold/reject decisioning with cost trade-offs, and specify experiment and monitoring plans, testing competencies in fraud analytics, operational risk modeling, and experimentation.

    Analytics & ExperimentationHR Screen
  • TikTokMediumData Scientist
    Balance Customer Satisfaction with Fraud Prevention: Key Metrics to Track

    Evaluates risk-decisioning trade-offs between customer experience and fraud prevention in payment products. Strong answers cover cost-sensitive thresholds, false declines, fraud loss, experimentation, monitoring, and delayed labels.

    Analytics & ExperimentationOnsite
  • TikTokHardData Scientist
    Design A/B Test for Cost-Per-Conversion Efficiency Analysis

    Design A/B Test for Cost-Per-Conversion Efficiency Analysis 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
  • TikTokMediumData Scientist
    Design Metrics for Content Moderation and Chatbot Evaluation

    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 Metrics for Content Moderation and Chatbot Evaluation states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • TikTokMediumData Scientist
    Design a creator posting-frequency experiment

    This problem tests the ability to design a controlled experiment while accounting for network interference, non-compliance, and selection bias in a two-sided platform.

    Analytics & ExperimentationOnsiteExperimentationA/B TestingCausal Inference
  • TikTokHardData Scientist
    Design an experiment for exploratory recommendations

    Evaluates experiment design for exploratory recommendation algorithms that may trade short-term engagement for discovery. Strong answers define exploration, satisfaction, retention, ecosystem health, leading indicators, and cautious launch decisions.

    Analytics & ExperimentationTechnical Screen
  • TikTokHardData Scientist
    Design an interference-robust A/B test for monetization

    This question evaluates experimental design and causal inference skills within Analytics & Experimentation, emphasizing interference mitigation, clustering and randomization choices, eligibility and exposure rules, metric hierarchy and guardrails, power and duration planning, variance-reduction techniques, and cluster-robust inference in a two-sided marketplace. It is commonly asked to test a data scientist's practical-application ability to balance monetization and growth trade-offs through precise statistical planning, pre-registered stopping rules, SRM detection, MDE and rollout decision thresholds rather than purely conceptual understanding.

    Analytics & ExperimentationHR Screen
  • TikTokHardData Scientist
    Design robust A/B test with interference and seasonality

    This question evaluates expertise in experimental design, causal inference, statistical power and minimum detectable effect calculation, variance-reduction techniques, sequential monitoring, and diagnostics for interference, spillovers, and weekly seasonality in A/B testing.

    Analytics & ExperimentationTechnical Screen
  • TikTokMediumData Scientist
    Diagnose Search Issues with Relevant Metrics and Solutions

    Evaluates diagnosis of brand-name search relevance and safety issues using analytics and experimentation. Strong answers define relevance, satisfaction, and harmful-content metrics, find root causes, and validate fixes offline and online.

    Analytics & ExperimentationOnsite
  • TikTokMediumData Scientist
    Diagnose Traffic Allocation in A/B Test Results

    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 Diagnose Traffic Allocation in A/B Test Results states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • TikTokHardData Scientist
    Diagnose metric drop in Ads Manager

    This question evaluates a Data Scientist's competency in operational analytics, metric integrity, root-cause analysis, and experiment interpretation, covering concepts such as logging latency, sample ratio assessment, and product instrumentation awareness.

    Analytics & ExperimentationOnsite
  • TikTokEasyData Scientist
    How would you measure misinformation impact and recommendation bias?

    This question tests the ability to design an evaluation framework for identifying algorithmic bias and measuring the reach of misinformation within a content recommendation system.

    Analytics & ExperimentationTechnical ScreenAnalyticsRecommendation SystemsMetrics
  • TikTokMediumData Scientist
    Improve TikTok's Algorithm for Diverse Content Discovery

    Evaluates product feedback and experiment design for improving content discovery in TikTok-style feeds. Strong answers propose specific improvements, justify impact, define metrics, and plan experiments with guardrails.

    Analytics & ExperimentationOnsite
  • TikTokMediumData Scientist
    Investigate Traffic Distribution Impact on Retention Decrease

    Evaluates A/B test diagnostics for a retention decrease after a button-color change. Strong answers check allocation, balance, logging, maturation, statistical robustness, segments, and decision criteria before blaming treatment.

    Analytics & ExperimentationTechnical Screen
  • TikTokHardData Scientist
    Investigate visit–report correlation causality

    This question evaluates a candidate's competency in causal inference, experimental design, diagnostic analytics, and statistical modeling with ad-level observational data.

    Analytics & ExperimentationTechnical Screen
  • TikTokHardData Scientist
    Measure Billboard Campaign Effectiveness and Engagement Quantification

    Evaluates offline marketing measurement for a billboard campaign, including how to define attributable engagement, estimate exposed population, and forecast incremental traffic, sign-ups, retention, revenue, and ROI. Strong answers use geo-lift, matched markets, or synthetic controls rather than direct attribution alone.

    Analytics & ExperimentationOnsite
  • TikTokHardData Scientist
    Prove conversion ads value via incrementality

    This question tests your ability to design a robust incrementality experiment to measure the causal impact of advertising, accounting for selection bias and interference.

    Analytics & ExperimentationTechnical ScreenCausal InferenceA/B TestingAds Measurement
  • TikTokHardData Scientist
    Test 15s to 60s video length change

    This question evaluates a data scientist's competency in experimental design, causal inference, metric definition and instrumentation, power/MDE calculations, interference and contamination handling on multi‑sided platforms, and rollout planning.

    Analytics & ExperimentationOnsite
  • Tools For HumanityEasyData Scientist
    Detect and evaluate "stolen" posts

    This question evaluates data-science competencies in instrumentation and feature design, content-similarity detection and labeling, causal inference for experiments, measurement of harms, and model evaluation, and belongs to the Analytics & Experimentation domain.

    Analytics & ExperimentationTechnical Screen
  • TubiHardData Scientist
    Determine A/B test sample size drivers

    This question evaluates statistical power and sample size determination for A/B testing, covering hypothesis testing for proportions, derivation using normal approximations, the impact of MDE, α and power choices, allocation ratios, cluster design (ICC and design effect), group‑sequential monitoring, and adjustment for overdispersed count outcomes.

    Analytics & ExperimentationTechnical Screen
  • TubiHardData Scientist
    Handle multiple experiment metrics and communication

    This question assesses the ability to design a multi-metric experiment, manage the false positive rate under multiple testing, and communicate trade-off decisions to non-technical stakeholders.

    Analytics & ExperimentationTechnical ScreenA/B TestingStatistical SignificanceMultiple Comparisons
  • TuroHardData Scientist
    Identify Booking Drivers

    This question evaluates skills in product analytics, causal inference, feature importance modeling, metric definition, and experimental validation within a marketplace context.

    Analytics & ExperimentationOnsite
  • UberMediumData Scientist
    Design Pricing Model Experiment

    This question evaluates experimental design and causal inference competencies for marketplace pricing, covering metric selection, guardrail definition, interference and switchback designs, and sample-size and treatment-window tradeoffs.

    Analytics & ExperimentationTechnical Screen
  • UberMediumData Scientist
    Design Rideshare Marketplace Causal Analyses

    This question evaluates a data scientist's skills in experimental design and causal inference, marketplace metrics and diagnostics, fairness and safety impact assessment, incentive and policy evaluation, and ETA modeling and forecast quality measurement.

    Analytics & ExperimentationOnsite
  • UberHardData Scientist
    Design an ETA experiment under interference

    This question evaluates a data scientist's competency in experimental design and causal inference for two-sided marketplaces, focusing on interference, partial compliance, metric definition, randomization strategy, instrumentation, estimation, and power calculations within the Analytics & Experimentation domain.

    Analytics & ExperimentationTechnical Screen
  • UberHardData Scientist
    Design an experiment with marketplace network effects

    This question evaluates a candidate's competency in causal experiment design for networked two‑sided marketplaces, focusing on interference and spillover management, cluster randomization choices, metric definition, power/sample‑size calculations, bias‑reduction approaches, and diagnostic checks.

    Analytics & ExperimentationTechnical Screen
  • UberEasyData Scientist
    Design and Test a New Feature

    This question evaluates a candidate's ability to design a new product feature for a ride-hailing platform and to translate product goals into measurable outcomes, testing competencies in product sense, metric definition, experiment and causal-inference design, segmentation, and two-sided marketplace trade-off analysis.

    Analytics & ExperimentationOnsite
  • UberHardData Scientist
    Design and power an incentive experiment

    This question evaluates experimental design, causal inference, A/B testing and statistical power calculation skills, including defining eligibility, unit of randomization, treatment arms, stratification, metric selection with guardrails, handling noncompliance and interference, and interpreting heterogeneous treatment effects.

    Analytics & ExperimentationOnsite
  • UberHardData Scientist
    Design promo experiment and explain correlation

    This problem tests your ability to distinguish correlation from causation in observational data and to design a robust A/B test to measure the incremental impact of a new rider promotion.

    Analytics & ExperimentationTechnical ScreenCausal InferenceA/B TestingExperimentation
  • UberMediumData Scientist
    Determine Sample Size for Promotion Campaign A/B Test

    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 Sample Size for Promotion Campaign A/B Test states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen