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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 1831–1860 of 1971 results
- UberMediumData ScientistEvaluate business value of lower ETA
This question tests the ability to design an experiment that isolates the causal impact of reduced ETA on user retention and to translate these metrics into business value.
Analytics & ExperimentationTechnical ScreenExperimentationCausal InferenceMarketplace Analytics - UberHardData ScientistEvaluate impact without randomized experiments
This question evaluates a data scientist's competence in causal inference and identification strategies for estimating promotion effects from observational longitudinal data, emphasizing challenges such as staggered rollout, interference (spillovers), seasonality, and uncertainty quantification.
Analytics & ExperimentationTechnical Screen - UberMediumData ScientistEvaluate marketplace interventions
This question tests the ability to design an experimentation framework for a two-sided marketplace, specifically addressing interference between supply and demand and selecting appropriate success metrics.
Analytics & ExperimentationOnsiteExperimentationMarketplaceCausal Inference - UberHardData ScientistExplain and validate A/B test assumptions
This question evaluates proficiency in experimental design, causal inference, and statistical diagnostics for A/B testing, covering competencies such as randomization integrity, SUTVA/interference, noncompliance, time-varying effects, metric missingness, sequential testing, and heterogeneous treatment effects.
Analytics & ExperimentationTechnical Screen - UberMediumData ScientistFind the Next Larger Palindrome
This question evaluates proficiency in numeric and string manipulation, algorithmic thinking, and edge-case reasoning related to palindromic number generation.
Coding & AlgorithmsOnsite - UberMediumData ScientistFormulate OR model to reduce driver backtracking
This question evaluates skills in defining a quantitative driver-backtracking metric from GPS and assignment logs, detecting and validating backtracking segments, and formulating constrained optimization models for dispatch and repositioning, drawing on statistics, operations research, and stochastic optimization.
Statistics & MathOnsite - UberHardData ScientistFormulate hypotheses and compute AB test significance
This question evaluates a data scientist's competency in experimental design and statistical inference for A/B testing, covering hypothesis formulation, difference-in-proportions testing and confidence intervals, guardrail analysis, multiple-testing correction, interim alpha-spending approaches, and variance-reduction techniques such as CUPED.
Statistics & MathTechnical Screen - UberEasyData ScientistHow to experiment on ETA reduction
This problem tests the ability to design an A/B test for product improvements and address potential confounding factors like selection bias and spillover effects.
Analytics & ExperimentationTechnical ScreenA/B TestingCausal InferenceMarketplace Dynamics - UberMediumData ScientistHow would you build UberEats ranking?
This question assesses the ability to design an end-to-end ranking system for a food delivery platform, focusing on objective formulation, feature selection, and the trade-offs between relevance and business constraints.
Machine LearningTechnical ScreenRecommender SystemsLearning to RankFeature Engineering - UberEasyData ScientistHow would you design an ETA prediction system?
This problem tests the ability to design an end-to-end machine learning system for predicting ride arrival times, focusing on feature selection, model architecture, and evaluation strategies.
Machine LearningTechnical ScreenML System DesignRegressionFeature Engineering - UberMediumData ScientistImplement FizzBuzz
This problem tests foundational programming skills by requiring the implementation of conditional logic and string manipulation based on modular arithmetic patterns.
Coding & AlgorithmsOnsiteAlgorithmsControl FlowStrings - UberMediumData ScientistImplement Streaming Clustering for Numbers
This question evaluates a data scientist's competency in online clustering for numeric streams, testing understanding of streaming algorithms, bounded-memory cluster summaries, online updates, and issues including initialization, convergence behavior, outlier handling, and concept drift.
Machine LearningOnsite - UberMediumData ScientistImplement weighted sampling without replacement
This question evaluates a candidate's ability to design numerically stable, streaming weighted-sampling methods and tests competencies in randomized algorithms, probability, numerical analysis, and memory/time trade-offs.
Coding & AlgorithmsTechnical Screen - UberHardData ScientistImprove Estimated Time of Arrival for Uber Riders
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 Improve Estimated Time of Arrival for Uber Riders states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - UberHardData ScientistInvestigate ride declines and test free trials
This question evaluates proficiency in product analytics, cohort and funnel analysis, retention and supply diagnostics, pricing and subscription economics, and experimentation design.
Analytics & ExperimentationOnsite - UberEasyData ScientistMeasure feature impact with switchback, PSM, and CACE
This question evaluates proficiency in causal inference and experimental design for product metrics, specifically testing knowledge of switchback experiments, time-series adjustments (seasonality and autocorrelation), propensity score methods for observational comparisons, and complier-average causal effect (LATE/CACE) estimation; it belongs to the Analytics & Experimentation and Data Science domain. It is commonly asked because it probes handling of real-world complications—time and city heterogeneity, non-compliance, and derived-metric inference—and tests both conceptual understanding of causal assumptions and practical application of statistical adjustment and inference.
Analytics & ExperimentationTechnical Screen - UberHardData ScientistMeasure rider incentive causal ROI
This question evaluates a data scientist's competency in causal inference and experimental design, marketplace health metric construction, ROI estimation, and the handling of selection bias, spillover effects, multiple testing, and heterogeneity in two-sided platforms.
Statistics & MathTechnical Screen - UberMediumData ScientistMove zeros to front
This problem tests your ability to manipulate array indices in-place to reorder elements according to a specific condition while maintaining relative stability.
Coding & AlgorithmsTechnical ScreenArraysTwo-PointersIn-place - UberHardData ScientistNavigate urgency, priorities, and conflict
This question evaluates a candidate's ability to manage ambiguity, prioritize competing projects and deadlines, navigate cross-team dependencies, influence stakeholders without formal authority, and quantify outcomes and process improvements.
Behavioral & LeadershipTechnical Screen - UberMediumData ScientistShould Uber double member discounts?
This problem tests your ability to design a controlled experiment for a two-sided marketplace and evaluate whether a discount-doubling strategy is statistically and economically viable.
Statistics & MathTechnical ScreenA/B TestingCausal InferenceMarketplace Economics - UberMediumData ScientistWrite SQL and Pandas for Uber Trips
This question evaluates SQL and Pandas data manipulation competencies, including joins, time-based filtering, handling NULLs, aggregations, rate and ratio calculations, and windowed comparisons over grouped city-day data.
Data Manipulation (SQL/Python)Technical Screen - UberMediumData ScientistWrite SQL/Python for CTR analytics
This question evaluates proficiency in data manipulation and analytics, covering SQL windowing and deduplication for time‑windowed cohort metrics (48‑hour unique CTR) as well as practical Python model evaluation tasks such as precision‑recall plotting, weighted F1 threshold selection, and precision@top‑k.
Data Manipulation (SQL/Python)Technical Screen - UpstartMediumData ScientistAnalyze HT vs HH stopping-time probabilities
This question evaluates understanding of discrete probability, stopping-time analysis, pattern occurrence in Bernoulli sequences, derivation of PMFs and expectations, and the ability to generalize results to biased coins.
Statistics & MathTechnical Screen - UpstartEasyData ScientistAssess Probability of Heads in Coin Tosses
Assess Probability of Heads in Coin Tosses evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - UpstartMediumData ScientistCalculate Average Event Value by User ID
This question evaluates a candidate's skill in group-wise aggregation and data transformation on JSON-like event streams, specifically computing per-user average metrics and producing ranked results.
Data Manipulation (SQL/Python)Technical Screen - UpstartEasyData ScientistCalculate Expected Streaks in Coin Toss Sequence
Calculate Expected Streaks in Coin Toss Sequence evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - UpstartEasyData ScientistCalculate Particle Survival Probability After Time t
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Particle Survival Probability After Time t states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathTechnical Screen - UpstartMediumData ScientistCalculate User Revenue and Session Duration in Python
This question evaluates proficiency in data manipulation and time-series event processing in Python, focusing on per-user revenue aggregation and sessionization to compute average session duration.
Data Manipulation (SQL/Python)Technical Screen - UpstartEasyData ScientistCombine noisy thermometers; compute random-walk correlations
This question evaluates estimation and probabilistic reasoning skills, specifically the construction of unbiased estimators and variance-minimizing linear combinations for combining noisy measurements, together with computation and asymptotic characterization of correlations in a 2D simple random walk.
Statistics & MathOnsite - UpstartEasyData ScientistCompute decay, OLS, and classic probability results
This question evaluates probability and statistical modeling skills—probabilistic reasoning for exponential decay and the coupon-collector expectation, derivation of population OLS coefficients for simple linear models, simulation implementation, and conditional probability reasoning exemplified by the Monty Hall scenario.
Statistics & MathOnsite