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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 361–390 of 513 results
- NetflixMediumData ScientistEstimate ATE of personalization on streaming
This question evaluates causal inference and experimental-analysis competencies by asking for estimation of the average treatment effect (ATE) of personalization on minutes streamed, reporting a 95% confidence interval, and reasoning about the use of pre-treatment covariates, and it sits in the Analytics & Experimentation domain for a Data Scientist role. It is commonly asked to assess application of randomized experiment analysis and statistical inference while probing conceptual understanding of causal assumptions and covariate adjustment, testing both conceptual understanding and practical application.
Analytics & ExperimentationOnsite - NetflixEasyData ScientistEstimate ATE, ITT, and TOT from experiment
This question tests the ability to distinguish and calculate Average Treatment Effect (ATE), Intent-to-Treat (ITT), and Treatment-on-the-Treated (TOT) in the presence of non-compliance.
Analytics & ExperimentationOnsiteCausal InferenceExperimentationInstrumental Variables - NetflixMediumData ScientistHow to Design Effective A/B Tests for Onboarding
Evaluates A/B test design for a redesigned onboarding flow in a subscription app. Strong answers define activation, user-level randomization, primary and guardrail metrics, sample size, sequential monitoring, and decisions when activation improves but support burden rises.
Analytics & ExperimentationOnsite - NextdoorMediumData ScientistMeasure Local News Launch Success
This problem tests your ability to design an experimentation framework for a localized product launch and identify potential confounding factors and interference effects.
Analytics & ExperimentationTechnical ScreenExperimentationCausal InferenceMetrics - OneMain FinancialMediumData ScientistCalculate Break-Even Point and Profit Impact 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 Calculate Break-Even Point and Profit Impact Analysis states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - OneMain FinancialEasyData ScientistCalculate Break-even for New Credit Card Product 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 Calculate Break-even for New Credit Card Product Launch states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - OneMain FinancialMediumData ScientistCalculate Profit-Maximizing Price and Validate with Additional Data
Evaluates profit-maximizing pricing from demand curves, marginal revenue, marginal cost, and validation data. Strong answers derive optimal price and quantity, provide examples, and request experiments or elasticity evidence.
Analytics & ExperimentationOnsite - OneMain FinancialMediumData ScientistDetermine Channel Performance with Additional Metrics Needed
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 Channel Performance with Additional Metrics Needed states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - OneMain FinancialMediumData ScientistDetermine Optimal Marketing Budget Allocation for Maximum Profit
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 Optimal Marketing Budget Allocation for Maximum Profit states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnline Assessment - OneMain FinancialEasyData ScientistEvaluate shift from branch to digital channel
This question evaluates a data scientist's ability to analyze channel unit economics, design growth experiments and metrics, and assess operational, fraud, and credit risk implications for shifting acquisition from branch to digital in a credit-card business.
Analytics & ExperimentationTechnical Screen - OneMain FinancialMediumData ScientistMaximize credit card portfolio profit
This problem tests your ability to model expected profitability by balancing credit risk (probability of default) against revenue generation and defining optimal decision thresholds.
Analytics & ExperimentationTechnical ScreenCredit RiskProfit ModelingDecision Strategy - OneMain FinancialMediumData ScientistOptimize SaaS pricing and profit
This question evaluates pricing optimization, linear demand modeling, capacity-constrained profit maximization, and the impact of subscription churn on lifetime value within an Analytics & Experimentation data-science context.
Analytics & ExperimentationTechnical Screen - OpenAIMediumData ScientistAnalyze A/B Test Results for Subscription Conversion Rates
Evaluates A/B test analysis for a limited-time free trial offer. Strong answers compute paid-conversion lift, account for trial starts and churn, test statistical significance, and make a launch decision using retained paid value, revenue, guardrails, and long-term holdouts.
Analytics & ExperimentationOnline Assessment - OpenAIHardData ScientistAssess free-month promotion impact
This question tests your ability to design a rigorous experimentation framework to measure the causal impact of a promotional offer while accounting for self-selection bias and long-term churn behavior.
Analytics & ExperimentationTechnical ScreenA/B TestingCausal InferenceProduct Analytics - OpenAIHardData ScientistDesign a free-month experiment
This question evaluates experimental design, causal inference, metric selection, bias mitigation, ROI estimation, and stakeholder communication skills within the Analytics & Experimentation domain for a Data Scientist role.
Analytics & ExperimentationTechnical Screen - OpenAIHardData ScientistDesign and Defend a Free-Trial Conversion Analysis
Walk through how to plan, execute, and defend a free-trial conversion analysis end to end: cohort definition, data-quality checks, standards for a credible insight, and a recommendation deck that survives live pushback.
Analytics & ExperimentationOnsiteexperimentationmetricscase-study - OpenAIMediumData ScientistDetermine Metrics to Measure Free-Trial Impact on Subscriptions
Determine Metrics to Measure Free-Trial Impact on Subscriptions 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 & ExperimentationOnline Assessment - OpenAIEasyData ScientistEvaluate a free-trial A/B test
This question tests your ability to design an A/B test for a freemium product, interpret statistical results, and address potential biases like cannibalization or selection effects.
Analytics & ExperimentationTechnical ScreenA/B TestingMetricsRetention - OpenAIMediumData ScientistHow would you evaluate a free-trial A/B test?
Evaluates skills in A/B test design and causal inference within the Analytics & Experimentation domain, emphasizing precise metric definition (including guardrails), choice of analysis population (ITT vs per‑protocol), handling of post‑treatment selection, and interpretation of binary conversion and retention metrics; the abstraction level is technical and oriented toward intermediate-to-senior data scientists who must combine statistical rigor with product impact thinking. Commonly asked because it tests the ability to balance acquisition versus downstream retention and revenue, to identify typical analysis pitfalls (time-window errors, incorrect joins/denominators, leakage, peeking, and selection bias), and to translate experiment results into a business recommendation linked to value metrics like LTV and payback period.
Analytics & ExperimentationTechnical Screen - OpenAIHardData ScientistMeasure free-month promotion impact
This question tests the ability to design an experiment for a subscription product, focusing on causal inference, handling right-censoring in cohort data, and calculating the Return on Investment (ROI) for a promotional offer.
Analytics & ExperimentationTechnical ScreenCausal InferenceExperiment DesignROI - OtherHardData ScientistDecide launch with asymmetric costs
This question evaluates a data scientist's ability to integrate statistical inference (p‑values, Type I/II errors, and prior probabilities) with decision analysis and financial impact assessment (NPV, rollout and rollback costs) in the context of A/B testing.
Analytics & ExperimentationTechnical Screen - OtherHardData ScientistDefine goals and success metrics for subscriber-only features
This question evaluates a data scientist's competency in product analytics and experimentation, specifically goal selection, success metric definition, ROI calculation, cannibalization analysis, and end-to-end experiment and instrumentation design for subscriber-only features.
Analytics & ExperimentationTechnical Screen - OtherHardData ScientistDesign an A/B test with guardrails
This question evaluates a data scientist's skills in experimental design, hypothesis testing, statistical power and sample-size calculation, randomization and contamination control, pre-registration planning, and multiplicity adjustment for A/B testing.
Analytics & ExperimentationOnsite - OtherHardData ScientistDesign metrics and experiment
This question evaluates a candidate's competency in experimental design, success-metric definition, event instrumentation, causal inference for heterogeneous treatment effects, and statistical power and sample-size calculations for subscription-product analytics.
Analytics & ExperimentationTechnical Screen - OtherMediumData ScientistDesign metrics resilient to data quality
This question evaluates the ability to design robust data-quality metrics and apply SQL window-function techniques for deduplication and time-windowed completeness calculations, focusing on quantifying how ingestion delays, duplicates, and negative amounts can bias payment metrics.
Analytics & ExperimentationTechnical Screen - OtherEasyData ScientistHow would you measure and experiment on harmful content?
This question evaluates a data scientist's competency in measuring and experimenting on harmful user-generated content, focusing on severity quantification, metric selection, and randomized experiment design within the analytics and experimentation domain.
Analytics & ExperimentationTechnical Screen - OtherMediumData ScientistSeparate demand from supply for jeans
This question evaluates a data scientist's ability to perform data-driven diagnostics, funnel-metric construction, quantitative decision-rule design, and experimentation planning to distinguish demand-side from supply-side constraints in a marketplace jeans category.
Analytics & ExperimentationOnsite - PayPalMediumData ScientistAnalyze Transactions for Risk and Implement Mitigation Strategies
Analyze Transactions for Risk and Implement Mitigation Strategies 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 - PayPalHardData ScientistAssess card transactions and plan risk strategy
Assess card transactions and plan risk strategy 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 - PayPalMediumData ScientistBoost User Login Rate: Key Metrics to Monitor
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 Boost User Login Rate: Key Metrics to Monitor states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite