Data Scientist Interview Questions

Showing 781–810 of 1076 results

• PRPlymouth Rock Assurance CorporationMedium·Data Scientist
  Calculate Ultimate Loss by Policy Term

  This question evaluates a candidate's ability to perform sequence-aware cumulative aggregation and partitioned data manipulation, assessing competency in calculating running totals (ultimate loss) across policy-term records.

  Data Manipulation (SQL/Python)Technical Screen
• Point72Medium·Data Scientist
  Classify relationships for multiple circle pairs

  This question evaluates computational geometry skills, careful integer arithmetic for numeric precision, case-based classification logic, and analysis of time and space complexity in the Coding & Algorithms domain for Data Scientist roles.

  Coding & AlgorithmsTechnical Screen
• Point72Medium·Data Scientist
  Convert Dates to Calendar Quarter Labels in SQL/Python

  This question evaluates a candidate's ability to perform date/time data transformation and normalization in SQL or Python, focusing on converting raw numeric dates into standardized quarter labels for aggregation and reporting.

  Data Manipulation (SQL/Python)Technical Screen
• Point72Medium·Data Scientist
  Determine Circle Intersection Status for Rendering Order

  This question evaluates geometric reasoning and computational-geometry competency, including spatial relationship analysis and handling numerical edge cases relevant to pairwise object interaction.

  Coding & AlgorithmsTechnical Screen
• Point72Hard·Data Scientist
  How would you explain PCA and SHAP?

  A Point72 Data Scientist technical screen asking you to defend one end-to-end ML project: problem framing and label timing, leakage controls, time-based validation, feature engineering, hyperparameter tuning, dimensionality reduction with PCA, and model interpretability with SHAP. Expects the PCA optimization objective and SVD link, the Shapley principle behind SHAP, plot interpretation, and the pitfalls of each.

  Machine LearningTechnical Screen
• Point72Medium·Data Scientist
  Maximize outfits with distinct colors

  This question evaluates competency in combinatorial optimization and constrained resource-allocation algorithms, along with analysis of time and space complexity and robustness to skewed input distributions and edge cases.

  Coding & AlgorithmsTechnical Screen
• Point72Medium·Data Scientist
  Write SQL for top student per department

  This question evaluates proficiency in SQL query formulation, including group-wise selection, joins, NULL handling, deterministic tie-breaking and ordering to identify a top-per-group student.

  Data Manipulation (SQL/Python)Technical Screen
• QQuoraMedium·Data Scientist
  Test a Post-Creation Tab While Accounting for User Interference

  Design an experiment for a post-creation tab with creator–reader spillovers, cluster-aware analysis and an evidence-based launch decision.

  Analytics & ExperimentationTechnical Screen
• RedditHard·Data Scientist
  Communicate and de-risk a non-experimental launch

  This question evaluates a data scientist's competency in interpreting causal-inference results from a Synthetic Control, communicating evidence strength and residual risks to executives and skeptical partners, structuring rollout governance and rollback criteria, and managing bias control, dissent and cross-functional accountability.

  Behavioral & LeadershipTechnical Screen
• RedditHard·Data Scientist
  Justify synthetic control and handle inference

  This question evaluates understanding of synthetic control methodology, causal identification assumptions, estimation and regularization choices, inference techniques for pointwise and cumulative effects, and diagnostic checks for panel time-series interventions.

  Statistics & MathTechnical Screen
• RedditMedium·Data Scientist
  Query US-based users and most active forums

  This question evaluates SQL data manipulation skills, including time-based filtering, joins, aggregations, null-safe handling, ratio computation, distinct counts, and top-N ranking to determine user residency and forum activity.

  Data Manipulation (SQL/Python)Technical Screen
• RevolutEasy·Data Scientist
  Define Ultra success metrics and detect suspicious transactions

  This question evaluates a data scientist's ability to define primary, diagnostic, and guardrail metrics for a product launch and to design rule-based suspicious-transaction detection using available schema, emphasizing metric definition, defensible proxy selection, SQL-based data modeling, and financial-crime domain knowledge.

  Analytics & ExperimentationTechnical Screen
• RobinhoodMedium·Data Scientist
  Diagnose Decline in First Day Funding Rate

  Diagnose Decline in First Day Funding Rate 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 & ExperimentationTechnical Screen
• RobinhoodMedium·Data Scientist
  Identify Overlapping Sessions and Optimize Coverage

  This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Identify Overlapping Sessions and Optimize Coverage states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Coding & AlgorithmsTechnical Screen
• RobinhoodMedium·Data Scientist
  Identify Top Users with Declined Transactions in SQL

  This question evaluates proficiency in SQL data manipulation, specifically aggregation, window functions, rolling 24-hour time-window analytics, NULL handling, and conditional classification via CASE WHEN within a fraud/risk detection scenario.

  Data Manipulation (SQL/Python)Technical Screen
• RobinhoodMedium·Data Scientist
  Identify Transactions During 'Golden' Membership Period

  This question evaluates proficiency in temporal data manipulation and aggregation, covering SQL date-range joins, window functions for per-user ranking, and Python frequency counting of senders and receivers, and it falls under the Data Manipulation (SQL/Python) domain for data scientist roles.

  Data Manipulation (SQL/Python)Technical Screen
• RobinhoodMedium·Data Scientist
  List Transactions During Active 'Gold' Membership Period

  This question evaluates proficiency in SQL-based data manipulation and temporal reasoning, specifically the ability to correlate membership periods with transaction records using relational operations.

  Data Manipulation (SQL/Python)Technical Screen
• RobinhoodMedium·Data Scientist
  Write SQL and Python for transaction analytics

  This question evaluates data manipulation competency in SQL and Python, covering normalization of transaction direction, JOINs and CASE logic, window functions for ranking and aggregation, and designing single-pass counting algorithms for streaming-like inputs.

  Data Manipulation (SQL/Python)Technical Screen
• RobinhoodMedium·Data Scientist
  Write SQL to localize trading drop contributors

  This question evaluates proficiency in SQL-based data manipulation and analytics, including cohorting by signup month, daily aggregation of executed trades per active user, segmentation by platform and geolocation, and competency with joins, timestamps, and operational flags.

  Data Manipulation (SQL/Python)Technical Screen
• RobloxMedium·Data Scientist
  Compare ROW_NUMBER, RANK, and DENSE_RANK for Top-k Results

  Compare ROW_NUMBER, RANK, and DENSE_RANK with ties, exact-row limits, distinct score levels, and deterministic top-k semantics.

  Data Manipulation (SQL/Python)Technical Screen
• RobloxMedium·Data Scientist
  Compute ARPDAU/ARPPU by country

  This question evaluates data manipulation and analytics skills for computing user- and revenue-based metrics (ARPDAU, ARPPU), focusing on aggregation, multi-key joins, deduplication, time-window filtering, and correct revenue attribution.

  Data Manipulation (SQL/Python)Technical Screen
• RobloxHard·Data Scientist
  Demonstrate fit with quantified stories and motivations

  This question evaluates a Data Scientist's behavioral and leadership competencies, including storytelling with quantified impact, ownership of technical decisions, trade-off analysis, error detection and correction, motivation, team collaboration, and end-to-end project thinking.

  Behavioral & LeadershipTechnical Screen
• RobloxMedium·Data Scientist
  Derive variance and CTR confidence intervals

  This problem tests your understanding of statistical inference for binomial proportions, specifically calculating confidence intervals for Click-Through Rates (CTR) and understanding how to aggregate variability across multiple days.

  Statistics & MathTechnical ScreenStatisticsInferenceCTR
• RobloxMedium·Data Scientist
  Describe leading an ambiguous ads project

  This question evaluates a data scientist's end-to-end ownership, experimental and analytics skills in ads/growth contexts, including hypothesis formulation, metric and guardrail selection, trade-off reasoning, stakeholder alignment, conflict resolution, and quantifying impact.

  Behavioral & LeadershipTechnical Screen
• RobloxHard·Data Scientist
  Describe resolving revenue–UX metric conflict

  This question evaluates a data scientist's competency in metrics-driven product leadership, focusing on balancing monetization and user-experience metrics, quantitative trade-off analysis, experiment design, risk management, and cross-functional stakeholder decision-making.

  Behavioral & LeadershipTechnical Screen
• RobloxHard·Data Scientist
  Design experiment for homepage tab replacement

  This question evaluates experiment design and causal-inference competency for product changes that impact both end users and platform creators, covering randomization strategies, metric and guardrail selection, power calculations, and handling of novelty, navigation friction, and ecosystem interference.

  Analytics & ExperimentationTechnical Screen
• RobloxMedium·Data Scientist
  Evaluate Impact of New Roblox Homepage Tab

  Roblox data scientist experimentation prompt on evaluating a new homepage tab, including hypotheses, engagement funnel metrics, guardrails, power, duration, segmentation, cannibalization, and rollout criteria.

  Analytics & ExperimentationTechnical Screen
• RobloxEasy·Data Scientist
  Find maximum follow depth using recursion

  This question evaluates a candidate's competency with recursion, directed graph traversal, cycle detection, and memoization when computing longest-path depths in social-network-style follow graphs.

  Coding & AlgorithmsTechnical Screen
• RobloxMedium·Data Scientist
  Implement Python Function for Statistical Test P-Values

  This question evaluates proficiency in statistical hypothesis testing, p-value interpretation, and implementing distribution-based calculations (Z and Student-t) in code, and it falls under the Coding & Algorithms domain for data scientist roles.

  Coding & AlgorithmsTechnical Screen
• RobloxHard·Data Scientist
  Implement robust one/two-sided p-value function

  This question evaluates proficiency in statistical hypothesis testing, numerical computing, and numerical stability when implementing p-value calculations for z and t distributions, and it targets the Statistics & Math domain for a data scientist role.

  Statistics & MathTechnical Screen