Data Scientist Interview Questions

Showing 541–570 of 1971 results

• CitadelHard·Data Scientist
  Sort a nearly sorted array

  This question evaluates algorithmic problem-solving skills, specifically understanding sorting under constrained inputs and rigorous time and space complexity analysis.

  Coding & AlgorithmsOnsite
• CitadelMedium·Data Scientist
  Stabilize LLM inference and estimate needed repeats

  This question tests the ability to design an LLM inference pipeline that ensures result stability through statistical aggregation and estimates the minimum number of inference samples required to achieve a target confidence level.

  ML System DesignTechnical ScreenLLMInferenceStatistics
• CitadelMedium·Data Scientist
  Update No-Intercept Regression Slopes Across Batches

  Compute cumulative no-intercept regression slopes as paired data arrives in batches. Reuse running cross-products and sums of squares instead of refitting all historical rows.

  Coding & AlgorithmsTechnical Screen
• CCitibankMedium·Data Scientist
  Compute expected payoff of reroll dice game

  This question evaluates understanding of probability theory and expected-value computation in stopping-time processes, including conditioning and infinite-series reasoning, and also tests modeling of per-trial costs and break-even analysis.

  Statistics & MathOnline Assessment
• CCitibankMedium·Data Scientist
  Price options and bonds via binomial no-arbitrage

  This question evaluates competence in no-arbitrage pricing, risk-neutral valuation, early-exercise features of American versus European options, and short-rate tree bond valuation within the Statistics & Math domain.

  Statistics & MathOnline Assessment
• CCloudTrucksMedium·Data Scientist
  Calculate Average Rate and Cumulative Jobs by State

  This question evaluates competency in relational data manipulation and analytical SQL concepts—including joins, aggregation with DISTINCT counts, per-date averaging, rolling cumulative counts, and handling numeric edge cases—within the Data Manipulation (SQL/Python) domain for a data scientist role.

  Data Manipulation (SQL/Python)Technical Screen
• CoinbaseMedium·Data Scientist
  Calculate Conversion Lift CI

  This question tests the ability to derive and calculate a confidence interval for the difference in conversion rates between two groups, and to explain how this interval informs a business decision.

  Statistics & MathOnsiteStatisticsA/B TestingInference
• CoinbaseEasy·Data Scientist
  Calculate Expected Users Adopting Wallet Feature

  This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Calculate Expected Users Adopting Wallet Feature states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Statistics & MathTechnical Screen
• CoinbaseEasy·Data Scientist
  Calculate Expected Users Linking Coinbase Wallets

  Coinbase probability question covering Bernoulli indicators, expected wallet links, complement rule for at least one success, and conditional probability for two users linking wallets.

  Statistics & MathTechnical Screen
• CoinbaseMedium·Data Scientist
  Calculate a Confidence Interval

  This question evaluates a candidate's competency in statistical inference for A/B testing, specifically the construction and interpretation of confidence intervals for differences in proportions, and falls under the Statistics & Math domain relevant to Data Scientist roles; it tests practical application (deriving point estimates and standard errors) alongside conceptual understanding (assumptions behind normal approximation versus exact, score-based, or bootstrap intervals). Interviewers commonly ask this to assess ability to quantify treatment effects, reason about approximation validity and alternative interval methods, and distinguish between absolute and relative lift when reporting experimental results.

  Statistics & MathOnsite
• CoinbaseMedium·Data Scientist
  Compute adoption, latency, and cross-region transactions

  This question evaluates proficiency in SQL-based data manipulation and analytics, including calculating cohort adoption and transaction rates, performing date arithmetic for time-to-first-transaction, identifying cross-region transactions, and computing distributional percentiles.

  Data Manipulation (SQL/Python)Onsite
• CoinbaseMedium·Data Scientist
  Design Identity & Trust Experiment

  This problem tests your ability to design a robust A/B test for a high-stakes identity verification flow, focusing on balancing security metrics with user acquisition and handling potential network interference.

  Analytics & ExperimentationOnsiteA/B TestingProduct MetricsPower Analysis
• CoinbaseMedium·Data Scientist
  Design an Identity Trust Experiment

  This question tests your ability to design a randomized controlled trial to measure the impact of a new identity verification process on user trust and retention, while addressing potential network effects and platform bias.

  Analytics & ExperimentationOnsiteExperimentationCausal InferenceA/B Testing
• CoinbaseMedium·Data Scientist
  Detect sequence rule and repair anomaly

  This question evaluates a candidate's skill in sequence pattern recognition, algorithm design, complexity analysis, and robust integer arithmetic by requiring inference among arithmetic, alternating-difference, geometric, and Fibonacci-plus-constant models while tolerating at most one corrupted term under O(n) time and O(1) extra space constraints.

  Coding & AlgorithmsHR Screen
• CoinbaseHard·Data Scientist
  Diagnose a 20% retail revenue drop

  This question evaluates a data scientist's ability in revenue decomposition, diagnostic analytics, causal inference, and experimentation design, covering traffic×CVR×AOV breakdowns, post-purchase deductions, stockout impacts, rapid falsifiable checks, and difference-in-differences-style attribution.

  Analytics & ExperimentationTechnical Screen
• CoinbaseMedium·Data Scientist
  Diagnose a Sudden Revenue Decline: Analyses, Metrics, and Root-Cause Tests

  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 Diagnose a Sudden Revenue Decline: Analyses, Metrics, and Root-Cause Tests states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Analytics & ExperimentationTechnical Screen
• CoinbaseMedium·Data Scientist
  Estimate Super Bowl QR Code Scan Rate Using Historical Data

  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 Estimate Super Bowl QR Code Scan Rate Using Historical Data states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Analytics & ExperimentationTechnical Screen
• CoinbaseMedium·Data Scientist
  Estimate Viewer Engagement with Super Bowl QR Code Promo

  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 Estimate Viewer Engagement with Super Bowl QR Code Promo states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Analytics & ExperimentationTechnical Screen
• CoinbaseMedium·Data Scientist
  Explain handling pressure to bend rules

  This question evaluates a candidate's competency in ethical decision-making, risk assessment, regulatory compliance (including data governance and payroll/immigration constraints), stakeholder influence, and cross-functional communication under pressure.

  Behavioral & LeadershipHR Screen
• CoinbaseMedium·Data Scientist
  Implement Plus One

  This question evaluates array manipulation and numeric carry propagation skills, along with the ability to reason about time and space complexity when performing arithmetic on digit lists.

  Coding & AlgorithmsOnsite
• CoinbaseMedium·Data Scientist
  Increment Digit Array

  This question tests the ability to handle array-based arithmetic and carry propagation logic, specifically addressing edge cases like array resizing.

  Coding & AlgorithmsOnsiteArraysMathSimulation
• CoinbaseMedium·Data Scientist
  Investigate Anomalies in Coinbase Wallet Engagement Metrics

  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 Investigate Anomalies in Coinbase Wallet Engagement Metrics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Analytics & ExperimentationTechnical Screen
• CoinbaseEasy·Data Scientist
  Model Feature Adoption Probability for Users

  This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Model Feature Adoption Probability for Users states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Statistics & MathTechnical Screen
• CoinbaseMedium·Data Scientist
  Optimize no-penalty test strategy

  This problem tests your ability to model expected value under time constraints by balancing the probability of success per question against a limited resource pool.

  Statistics & MathHR ScreenProbabilityExpected ValueOptimization
• CoinbaseMedium·Data Scientist
  Solve Aptitude Test: Logical, Numerical, Verbal Reasoning

  This question evaluates logical, numerical, and verbal reasoning along with rapid pattern recognition and time-limited decision-making relevant to pre-employment aptitude screens for data science roles.

  Coding & AlgorithmsOnline Assessment
• CoinbaseHard·Data Scientist
  Solve the 12-coin balance puzzle

  This question evaluates understanding of combinatorial reasoning, information theory, and decision-tree construction for identifying a single counterfeit coin and whether it is heavier or lighter using constrained balance-scale observations.

  Statistics & MathTechnical Screen
• CoinbaseMedium·Data Scientist
  Write SQL and Python for funnels/retention

  This question evaluates SQL and Python data-manipulation skills, including event-to-session joins, temporal window filtering, deduplication, JSON metadata handling, and computation of funnel and retention metrics like daily unique users and conversion rates.

  Data Manipulation (SQL/Python)HR Screen
• CoinbaseMedium·Data Scientist
  Write SQL: sum values ≤ each row’s value

  This question evaluates proficiency in SQL aggregation, query optimization, and handling duplicate values when computing cumulative sums across rows. It is commonly asked to assess practical ability in the Data Manipulation (SQL/Python) domain to design scalable, efficient queries and demonstrates a focus on practical application of query-design and optimization rather than purely conceptual theory.

  Data Manipulation (SQL/Python)Onsite
• ConfluentMedium·Data Scientist
  Determine Tutorial Completion Rate by Variant in 7 Days

  This question evaluates a candidate's competency in data manipulation and event-based analytics, focusing on skills such as joining user and event tables, aggregating event data, and computing cohort completion metrics by variant.

  Data Manipulation (SQL/Python)Onsite
• ConfluentMedium·Data Scientist
  Evaluate Metrics and Randomization for Onboarding Tutorial Change

  Evaluate Metrics and Randomization for Onboarding Tutorial Change 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