practice a little every day, paws crossed ♡
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 331–360 of 1971 results
- Capital OneMediumData ScientistArticulate your most significant achievement
This question evaluates a Data Scientist's competency in demonstrating measurable impact, decision-making under constraints, experimental design, trade-off reasoning, and stakeholder management within the Behavioral & Leadership category of data science.
Behavioral & LeadershipTechnical Screen - Capital OneMediumData ScientistAssess Cultural Fit and Soft Skills in Interviews
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Assess Cultural Fit and Soft Skills in Interviews states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - Capital OneMediumData ScientistAssess Customer Value with Varied Contract Terms and Costs
Evaluates subscription contract unit economics across free periods, service costs, marketing costs, churn penalties, and fixed overhead. Strong answers compute customer value, portfolio value, and break-even acquisitions.
Analytics & ExperimentationOnsite - Capital OneHardData ScientistAssess transition and profitability under fossil-fuel constraints
This question evaluates competency in data-driven energy transition analysis, quantitative modeling of generation mixes, economic pro-formas, and strategic decision-making under regulatory constraints.
Behavioral & LeadershipTechnical Screen - Capital OneMediumData ScientistAudit flight data quality from metadata
This question evaluates data quality auditing competencies, including validation of timestamps and timezones, detection of label leakage and inconsistent units, provenance and schema enforcement, and hands‑on use of SQL/Python for dataset inspection.
Data Manipulation (SQL/Python)Onsite - Capital OneMediumData ScientistAutomate Python Virtual Environment Setup on Linux Terminal
This question evaluates proficiency in shell scripting and Linux terminal automation for Python virtual-environment setup, focusing on environment management, automation, and reproducibility skills relevant to data science workflows.
Coding & AlgorithmsOnsite - Capital OneEasyData ScientistBuild House Price Model Responsibly
This problem tests your ability to design a robust, fair, and scalable machine learning pipeline for house price prediction, emphasizing data preprocessing, model selection, and ethical oversight.
Machine LearningOnsiteSupervised LearningRegressionFairness - Capital OneHardData ScientistBuild a causal ML pipeline end-to-end
This question evaluates expertise in causal inference and policy learning, covering ATE/CATE estimation, heterogeneous treatment effect methods, off‑policy evaluation, overlap and sensitivity diagnostics, and operational deployment with fairness guardrails in the Analytics & Experimentation domain.
Analytics & ExperimentationOnsite - Capital OneMediumData ScientistBuild and evaluate donation propensity model
This question evaluates a data scientist's competency in profit-oriented predictive modeling, including conversion and donation-amount modeling, handling sparse and categorical features, calibration and uplift estimation, and offline policy evaluation under selection bias.
Machine LearningOnsite - Capital OneEasyData ScientistCalculate Annual Profit of Credit Card Portfolio
Evaluates annual profit calculation for a credit-card portfolio with monthly and annual revenue and cost components. Strong answers annualize figures, compute per-card profit, and scale to portfolio profit.
Statistics & MathHR Screen - Capital OneEasyData ScientistCalculate Incremental Customers for Marketing Spend Justification
Evaluates incremental customer calculations for partnership marketing spend justification. Strong answers derive break-even customers for fixed spend and required volume for variable-cost campaigns against a profit target.
Statistics & MathHR Screen - Capital OneMediumData ScientistCalculate Longest Transaction Streak for Each User
This question evaluates proficiency in data manipulation and time-series sequence analysis, specifically measuring the longest run of consecutive successful transactions per user from transactional logs.
Data Manipulation (SQL/Python)Technical Screen - Capital OneMediumData ScientistCalculate Profit and Analyze Vegan Burger Market Trends
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 Profit and Analyze Vegan Burger Market Trends states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - Capital OneEasyData ScientistCalculate Profitability and Break-Even for Lyft Partnership Campaign
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 Profitability and Break-Even for Lyft Partnership Campaign states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationHR Screen - Capital OneMediumData ScientistCalculate break-even new customers for a 30% Rent-a-Home discount
A Capital One data-scientist technical screen on break-even and unit economics for a 30%-off Rent-a-Home promotion. You set up and solve the break-even equation for incremental new customers, size it against the 2M cardholder base, then re-solve under spend-uplift assumptions and explain why the required count nearly doubles.
Statistics & MathTechnical Screen - Capital OneEasyData ScientistCalculate first-year profit margin
This question evaluates a data scientist's quantitative reasoning about unit economics and financial metrics, including understanding fixed versus variable costs and computing profit margin as a percentage.
Statistics & MathTechnical Screen - Capital OneEasyData ScientistCalculate profit and break-even across pricing models
This question evaluates understanding of unit economics, break-even analysis, and pricing-model effects on profitability by requiring computation of revenue, variable and fixed costs, and profit under per-GB and two-tier pricing scenarios.
Statistics & MathTechnical Screen - Capital OneHardData ScientistChallenge and validate assumptions
This question evaluates a data scientist's competency in identifying fragile business assumptions, conducting sensitivity analysis, and designing experiments and observational studies to validate parameters related to demand, price elasticity, cannibalization, supply constraints, labor learning curves, regional heterogeneity, and promotional decay.
Analytics & ExperimentationTechnical Screen - Capital OneEasyData ScientistClean and Merge Housing Data
This question tests the ability to clean messy housing datasets, handle inconsistent data types, and perform efficient left-joins with external reference data.
Data Manipulation (SQL/Python)OnsitePandasData CleaningSQL - Capital OneMediumData ScientistCompare Logistic Regression and Random Forest in Python
Design, evaluate, and contrast a Logistic Regression baseline and a Random Forest model on an imbalanced credit default prediction dataset in Python. Walk through pipeline design, validation strategy, probability calibration, decision thresholding, and production trade-offs.
Machine LearningTechnical ScreenClassificationModel EvaluationPipelines - Capital OneEasyData ScientistCompare average profit across mix scenarios
This question evaluates understanding of expected value, weighted averages, and profit-margin analysis within the Statistics & Math domain for a Data Scientist role. It is commonly asked to probe quantitative reasoning about pricing and cost trade-offs, and it tests practical application of arithmetic and scenario-based profit modeling rather than abstract theoretical concepts.
Statistics & MathTechnical Screen - Capital OneEasyData ScientistCompare average unit profit under mix shift
This question tests the candidate's ability to calculate weighted averages and understand how changes in sales volume distribution (mix shift) affect the overall average profit per unit.
Statistics & MathTechnical ScreenStatisticsWeighted AverageUnit Economics - Capital OneMediumData ScientistCompute Customer Spend and Engineer Features for 2023
This question evaluates proficiency in SQL-based temporal aggregation and Python feature engineering on transactional datasets, including computing monthly spend summaries and engineering category-level spending features.
Data Manipulation (SQL/Python)Onsite - Capital OneEasyData ScientistCompute Groupon unit economics and break-even
A Capital One data science technical screen case on restaurant unit economics with a Groupon-style voucher. You compute baseline daily profit from a 20-table day, derive the break-even check for a voucher table under a $30-for-$15 offer with a 40% commission, profit a mixed 25-table day, and decompose the profit change into traffic, check size and voucher cost. Full worked arithmetic, a sensitivity solve, and the incrementality follow-ups an interviewer expects.
Statistics & MathTechnical Screen - Capital OneEasyData ScientistCompute Optimal Die Re-roll Strategy
This question tests the ability to calculate expected values and determine optimal decision thresholds in a multi-stage probabilistic game.
Statistics & MathOnsiteProbabilityExpected ValueDecision Theory - Capital OneMediumData ScientistCompute and interpret 95% confidence intervals
This question evaluates proficiency with confidence intervals, hypothesis testing for proportions and means, multiple-comparison adjustment (Bonferroni), and sample size calculations, including assessment of normal-approximation versus Wilson score methods.
Statistics & MathOnline Assessment - Capital OneMediumData ScientistCompute capacity, staffing trade-offs, and break-even
This question tests the ability to model operational costs, evaluate staffing trade-offs between overtime and contracting, and perform break-even analysis under varying volume assumptions.
Analytics & ExperimentationHR ScreenCapacity PlanningCost AnalysisOperations - Capital OneMediumData ScientistCompute credit-card portfolio profit and breakeven
This question evaluates financial modeling, unit-economics calculation, breakeven analysis, and basic risk/expected-loss estimation relevant to a Data Scientist, testing competency in statistics & math and algebraic derivation within financial analysis.
Statistics & MathOnsite - Capital OneEasyData ScientistCompute current annual profit
This question evaluates numerical proficiency in financial arithmetic, unit-aware quantitative reasoning, and per-customer business-metric computation within a loyalty program context.
Statistics & MathTechnical Screen - Capital OneMediumData ScientistCompute expansion profits and expected value
This question evaluates financial modeling, expected-value decision-making, probability reasoning, and sensitivity analysis skills applied to revenue, variable and fixed cost interactions and contractual fee impacts, aimed at a Data Scientist role.
Statistics & MathOnsite
Capital One