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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 1261–1290 of 1971 results

  • Morgan StanleyMediumData Scientist
    Explain Your Risk Analytics Work to a Recruiter

    This question tests your ability to translate complex technical risk modeling into a compelling professional narrative that emphasizes business impact, stakeholder collaboration, and personal accountability.

    Behavioral & LeadershipHR ScreenBehavioralRisk AnalyticsStakeholder Management
  • Morgan StanleyEasyData Scientist
    Explain forward contracts and options

    This question evaluates understanding of financial derivatives—specifically forwards and options—assessing competency in financial instruments, contractual rights and obligations, pricing concepts, and how these concepts inform data-driven modeling for a Data Scientist role.

    Software Engineering FundamentalsTechnical Screen
  • Morgan StanleyMediumData Scientist
    Implement Factorial and Squares

    A Morgan Stanley data scientist HR-screen live-coding warm-up: implement Python `factorial(n)` (iteratively, then explain the recursive version) and `squares(n)` returning the squares of the first n integers. Evaluates clean Python, the iteration-vs-recursion trade-off, time and space complexity analysis, input validation, and edge cases like n = 0 and negative input.

    Coding & AlgorithmsHR Screen
  • Morgan StanleyMediumData Scientist
    Solve Market-Risk and Probability Questions

    Morgan Stanley data-scientist HR-screen quant set covering four sub-questions: design a WTI/Brent crude stress-testing framework using heavy-tailed marginals and a t-copula for joint tail dependence; the variance of a sum of correlated normal variables and when the sum is normal; the Monty Hall switching probability; and the eight-balls one-heavier puzzle in two weighings. It probes both conceptual understanding and practical application of dependence modeling, scenario generation, and probabilistic reasoning.

    Statistics & MathHR Screen
  • MorningstarEasyData Scientist
    Explain a stochastic process simply

    This question assesses the candidate's ability to intuitively define a stochastic process, differentiate it from static probability models, and articulate fundamental properties like stationarity and the Markov property.

    Statistics & MathTechnical ScreenStatisticsStochastic ProcessesTime Series
  • NVIDIAHardData Scientist
    Demonstrate cultural fit and sales-oriented leadership

    This question evaluates cultural fit, sales-oriented leadership, customer-facing communication, stakeholder influence, conflict resolution, project failure analysis, product–business alignment, and career trajectory for a Data Scientist role.

    Behavioral & LeadershipHR Screen
  • NVIDIAHardData Scientist
    Design and explain robust web APIs for ML inference

    This question evaluates a candidate's proficiency in designing HTTP REST APIs for ML inference, including API endpoints, versioning, idempotency, request/response schemas, authentication/authorization, rate limiting, observability, and backward-compatibility policies, and it falls under the Coding & Algorithms domain for a data scientist role.

    Coding & AlgorithmsHR Screen
  • NVIDIAHardData Scientist
    Diagnose overfitting, DenseNet, preprocessing, CV

    This question evaluates a candidate's understanding of overfitting and mitigation techniques, comparative architecture knowledge between DenseNet and ResNet, leakage-free preprocessing and harmonization for medical imaging, practical CNN hyperparameter tuning, and cross-validation strategies.

    Machine LearningHR Screen
  • NVIDIAMediumData Scientist
    Explain NVIDIA fit and role value

    This question evaluates a candidate's cultural and role fit, ability to communicate measurable impact, skill in mapping past data-science projects to posted responsibilities, awareness of recent organizational initiatives, and adaptability to team culture.

    Behavioral & LeadershipHR Screen
  • NVIDIAHardData Scientist
    Implement CUDA-tiled matrix multiplication and explain architecture

    This question evaluates a candidate's competency in CUDA GPU programming, parallel algorithms, and performance engineering for FP32 matrix multiplication, covering tiling strategies, memory hierarchy (global/shared/register), synchronization, numerical precision, and occupancy/resource analysis.

    Coding & AlgorithmsHR Screen
  • NVIDIAHardData Scientist
    Optimize CUDA GEMM with tiling and coalescing

    This question evaluates proficiency in GPU programming and performance optimization, assessing understanding of the CUDA execution model, memory hierarchy and bank conflicts, occupancy limits, and practical kernel design concerns for single-precision GEMM including tiling, coalescing, vectorized memory accesses and benchmarking.

    Coding & AlgorithmsHR Screen
  • NVIDIAMediumData Scientist
    Reflect on interview takeaways and adaptation

    This question evaluates self-awareness, growth mindset, adaptive communication, and the ability to identify skill gaps and define measurable improvements within a Data Scientist interview context.

    Behavioral & LeadershipHR Screen
  • NVIDIAMediumData Scientist
    Resolve conflict and learn from failure

    This question evaluates a data scientist's cross-functional conflict resolution, stakeholder management, decision-framework literacy, quantitative impact measurement, ownership of failed projects, and ability to run postmortems and implement guardrails; it is categorized as Behavioral & Leadership within the Data Science domain and tests both conceptual understanding of decision-making frameworks and practical application of communication and metric-driven processes. It is commonly asked to assess interpersonal influence, accountability, learning from failure, and the capacity to convert lessons into measurable process, monitoring, or risk-control improvements that enhance decision quality.

    Behavioral & LeadershipHR Screen
  • NVIDIAHardData Scientist
    Reverse linked lists, including k-group

    This question evaluates understanding of linked list manipulation including pointer operations, in-place reversal techniques, recursion and stack-depth considerations, cycle detection, and time/space complexity analysis.

    Coding & AlgorithmsHR Screen
  • NVIDIAMediumData Scientist
    Sell GPUs to a retail CEO

    This question evaluates a candidate's ability to build a business and technical case for deploying GPUs across enterprise analytics and AI workloads, testing competencies in ROI/TCO modeling, workload discovery, pilot planning, stakeholder alignment, risk identification, and crafting data‑backed rebuttals.

    Behavioral & LeadershipHR Screen
  • NetflixMediumData Scientist
    Address Fraud Detection with Imbalance and Concept Drift Solutions

    Evaluates end-to-end fraud detection ML system design for online payments under drift and imbalance. Strong answers handle delayed labels, class imbalance, feature engineering, cost-sensitive validation, real-time deployment, threshold actions, monitoring, retraining, and concept drift.

    Machine LearningOnsite
  • NetflixMediumData Scientist
    Aggregate D1 retention cohorts in SQL

    This question evaluates a candidate's competency in time-series cohort analysis and SQL-based data manipulation, specifically measuring DAU, new-user cohorts, D1 retention and revenue-per-user while handling deduplication and user filtering.

    Data Manipulation (SQL/Python)Onsite
  • NetflixMediumData Scientist
    Analyze Retention Metrics Using SQL and Python

    This question evaluates proficiency in SQL time-based cohort analysis and practical Python algorithm implementation, testing retention metric computation using windowed date calculations and an efficient approach for finding two numbers whose sum is closest to zero.

    Data Manipulation (SQL/Python)Other
  • NetflixMediumData Scientist
    Answer core probability and statistics questions

    This question evaluates core probability and statistical inference competencies—covering Bayesian reasoning, regression controls and confounding, the Central Limit Theorem, distribution moments, t-statistics, and effect size/MDE—relevant to quantitative data analysis and hypothesis testing for a Data Scientist role in the Statistics & Math domain.

    Statistics & MathOnsite
  • NetflixMediumData Scientist
    Compute ITT, TOT, and LATE with noncompliance

    This question evaluates understanding of causal inference and experimental analysis, specifically estimation and interpretation of ITT, TOT, and LATE under noncompliance along with classification of compliance types (compliers, always-takers, never-takers, defiers).

    Analytics & ExperimentationOnsite
  • NetflixMediumData Scientist
    Critique culture memo and design probes

    This question evaluates a candidate's ability to operationalize organizational values, assess cultural signals, and design measurable diagnostics, reflecting competencies in leadership, stakeholder communication, ethical judgment, and metrics-driven decision-making.

    Behavioral & LeadershipHR Screen
  • NetflixHardData Scientist
    Demonstrate handling dismissive stakeholders with candor

    This question evaluates a candidate's competency in stakeholder management, candid communication under pressure, conflict de-escalation, requirement elicitation, and outcome-oriented leadership for a Data Scientist role.

    Behavioral & LeadershipOnsite
  • NetflixHardData Scientist
    Design A/B Test for Streaming Feature Network Effects

    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 A/B Test for Streaming Feature Network Effects states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOther
  • NetflixHardData Scientist
    Design a robust conversion propensity model

    This question evaluates a candidate's competency in end-to-end propensity modeling, covering correct labeling to avoid post-treatment leakage, time-windowed feature engineering, class-imbalance and calibration strategies, causal uplift estimation, and production concerns such as monitoring, serving consistency, and cold-start scoring.

    Machine LearningOnsite
  • NetflixMediumData Scientist
    Design experiment on culture memo emphasis

    This question tests the ability to design a rigorous A/B test for a qualitative product change, focusing on metric selection, potential bias mitigation, and pre-experimental planning.

    Analytics & ExperimentationHR ScreenA/B TestingExperiment DesignMetrics
  • NetflixMediumData Scientist
    Determine Maximum Consecutive Order Days Per User

    Determine Maximum Consecutive Order Days Per User evaluates SQL or pandas logic, joins, grouping, window functions, null handling, edge cases, and validation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Data Manipulation (SQL/Python)Onsite
  • NetflixMediumData Scientist
    Estimate 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 Scientist
    Estimate 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
  • NetflixHardData Scientist
    Evaluate Propensity Score Matching Alternatives and Diagnostics

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Evaluate Propensity Score Matching Alternatives and Diagnostics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathOther
  • NetflixMediumData Scientist
    How 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