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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 1021–1050 of 1971 results
- MetaMediumData ScientistCompute ad revenue metrics by geography in SQL
In the Data Manipulation (SQL/Python) domain, this intermediate-level question evaluates SQL aggregation, join logic between impressions and clicks, date-based UTC attribution, user-geo joins, and null/divide-by-zero-safe computation of derived metrics (CTR, RPM) at the country-day granularity.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute and correct correlation significance inflation
This question tests the understanding of how multiple hypothesis testing increases the risk of false positives (Type I error) in high-dimensional correlation matrices and requires the application of correction methods to maintain statistical integrity.
Statistics & MathTechnical ScreenStatisticsHypothesis TestingCorrelation - MetaMediumData ScientistCompute binary-tree diameter via return-only DFS
This question evaluates algorithmic problem-solving with binary trees, focusing on tree traversal techniques, recursion versus iterative implementations, and analysis of time and space complexity including worst-case input shapes such as skewed trees.
Coding & AlgorithmsTechnical Screen - MetaMediumData ScientistCompute cohort GMV and payer rate with edge cases
This question evaluates a data scientist's competency in cohort-based GMV calculation, payer-rate measurement, and handling common edge cases across events, orders, payments, and refunds.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute fraud probabilities with Bayes and Binomial
This question evaluates a candidate's understanding of probabilistic modeling and statistical decision-making, focusing on the Binomial distribution for session-level events and Bayes' theorem for posterior probabilities in a fraud-detection setting.
Statistics & MathOnsite - MetaEasyData ScientistCompute multi-account user distribution and unread pct
This question evaluates a data scientist's ability to perform relational data manipulation and aggregation with SQL or Python, covering competencies such as handling one-to-many joins, grouping and bucketing counts, deduplicating across related tables, and computing cohort-level percentages from boolean flags.
Data Manipulation (SQL/Python)Technical Screen - MetaHardData ScientistCompute p-values, power, and adjust errors
This question evaluates statistical reasoning and applied inference skills including hypothesis testing for proportions with sequential monitoring, multiple-testing control (Benjamini–Hochberg vs Bonferroni), Bayesian posterior estimation for classification flags, and robust AOV estimation and transformation techniques.
Statistics & MathOnsite - MetaMediumData ScientistCompute posterior and event counts in fraud screen
This question evaluates a candidate's competence in probability and statistical inference, covering binomial probability calculations, Bayes' theorem for posterior probability, rare-event base-rate reasoning, and modeling of correlated binary signals in a fraud-screening context.
Statistics & MathOnsite - MetaMediumData ScientistCompute posterior fake probability using Bayes' rule
The problem evaluates understanding of Bayes' rule and conditional probability within the Statistics & Math domain for a Data Scientist role, at an introductory applied probability/interpretation level.
Statistics & MathTechnical Screen - MetaEasyData ScientistCompute probabilities for chatbot response quality
This question evaluates a candidate's grasp of basic probability concepts, including independence, joint event probabilities, and i.i.d. assumptions. It is commonly asked to test probabilistic reasoning about repeated trials within the Statistics & Math domain and is primarily a conceptual understanding problem with a simple practical application.
Statistics & MathOnsite - MetaEasyData ScientistCompute probability an account is fake
This question tests the ability to apply Bayes' Theorem to update the probability of a hypothesis (an account being fake) given new evidence (an automated flag).
Statistics & MathTechnical ScreenBayesian StatisticsConditional ProbabilityClassification Metrics - MetaHardData ScientistCompute sample size and test duration correctly
This question evaluates competency in experiment design and statistical power calculations, including sample size estimation, variance misspecification effects, multiple-comparison corrections, sequential monitoring boundaries, and adjustments for covariates or clustering.
Statistics & MathTechnical Screen - MetaMediumData ScientistCompute shop visibility and intent metrics in SQL
This question evaluates SQL-based data manipulation and analytical competencies in the Data Manipulation (SQL/Python) domain, focusing on deduplication, time-zone-aware timestamp handling, window functions, aggregation, and construction of visibility, CTR, and intent metrics for shops.
Data Manipulation (SQL/Python)Technical Screen - MetaEasyData ScientistCompute this-year spend share of last-year whales
This question tests the ability to perform cohort analysis and time-based filtering to calculate the contribution of high-value segments across different fiscal years.
Data Manipulation (SQL/Python)OnsiteSQLAggregationCohort Analysis - MetaMediumData ScientistCompute time-spent percentage by app category
This question evaluates proficiency in data manipulation and analytics, specifically SQL/Python skills for joining tables, aggregating session durations, handling missing app-category mappings, and computing percentage time spent over a recent seven-day window.
Data Manipulation (SQL/Python)Onsite - MetaMediumData ScientistCompute unconnected 60s posts and reactions averages
This question evaluates data manipulation skills in SQL and Python, focusing on deduplication, join logic between event and reaction tables, date handling for string-typed dates, and aggregation to compute per-post metrics.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute unread and multi-account user percentages
This question evaluates understanding of SQL data manipulation skills such as aggregations, joins, NULL handling, deduplication reasoning, and user- versus person-level computations for accurate percentage metrics.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistCompute view prevalence from views and labels
This question evaluates a candidate's competency in temporal joins, stateful deduplication of moderation decisions, time-aware aggregation, and prevalence metric calculations within content-moderation analytics.
Data Manipulation (SQL/Python)Technical Screen - MetaMediumData ScientistConstruct a 95% Confidence Interval for Comment Counts
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Construct a 95% Confidence Interval for Comment Counts states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - MetaMediumData ScientistCount heavy callers in 7 days
This question tests the ability to handle temporal windowing and aggregation to identify user behavior patterns based on call activity frequency.
Data Manipulation (SQL/Python)Technical ScreenSQLWindow-FunctionsData-Manipulation - MetaMediumData ScientistDecide and experiment on Group Call feature
This question evaluates a data scientist's proficiency in product analytics, causal inference, metric engineering, experimentation design, and post‑launch diagnostics within the Analytics & Experimentation domain.
Analytics & ExperimentationTechnical Screen - MetaMediumData ScientistDecide event notification launch via experiments
This question tests the ability to design a robust A/B test in the presence of network effects, interference, and cannibalization within a social notification ecosystem.
Analytics & ExperimentationTechnical ScreenA/B TestingNetwork EffectsMetrics - MetaHardData ScientistDecide when CTR falls but revenue rises
This question evaluates understanding of A/B experimentation, auction-based ad metrics, metric decomposition for revenue impact, causal diagnostics for hidden heterogeneity (e.g., Simpson’s paradox), and executive-level results presentation within the Analytics & Experimentation domain.
Analytics & ExperimentationOnsite - MetaMediumData ScientistDefine Product Metrics: Align Stakeholders, Measure Success, Improve Results
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Define Product Metrics: Align Stakeholders, Measure Success, Improve Results states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - MetaMediumData ScientistDefine Success for a New Group Feature Without Hiding Cannibalization
Design a comprehensive measurement and experimentation framework for a new community feature, evaluating true incremental value while detecting cannibalization across existing surfaces and mitigating network spillover effects.
Analytics & ExperimentationTechnical Screenexperimentationmetric-designcannibalization - MetaMediumData ScientistDefine and compute shop visibility in SQL
This question evaluates the ability to define and compute shop-level visibility KPIs in SQL, testing skills in metric design (visibility_rate and impression_share), deduplication, session/window filtering, and data-quality concerns such as late-arriving events and bot filtering.
Data Manipulation (SQL/Python)Onsite - MetaEasyData ScientistDefine engagement metrics and analyze comment distribution
This question evaluates a data scientist's competency in metric framework design, distributional analysis of heavy-tailed user behavior, monitoring and anomaly detection, and experimental setup for measuring healthy engagement, including considerations like unit of analysis, treatment of heavy users, and anti-spam guardrails.
Analytics & ExperimentationOnsite - MetaHardData ScientistDeliver an elevator pitch and impact example
This question evaluates a data scientist's communication and leadership competencies, including concise elevator pitching, product sense, end-to-end experimentation design and statistical rigor, causal reasoning, and the ability to quantify measurable business impact within a product context.
Behavioral & LeadershipTechnical Screen - MetaMediumData ScientistDemonstrate leadership in cross-functional collaboration
The Meta Data Scientist onsite behavioral & leadership round: answer a set of STAR-format leadership prompts spanning cross-functional collaboration and conflict, giving/receiving feedback, disagree-and-commit, being wrong and course-correcting, overcoming obstacles and winning skeptics, driving breakthroughs, ambiguous work under time pressure, breaking-metric triage, learning from peers, diversity & inclusion, inclusive meetings, proactive alignment, and building long-term trust. Each answer must name stakeholders, state trade-offs, and quantify impact against a baseline.
Behavioral & LeadershipOnsite - MetaHardData ScientistDeploy multi-armed bandits safely
This question evaluates proficiency in online experimentation and sequential decision-making, covering Bayesian bandits (Thompson Sampling), safety guardrails for churn, delayed-conversion handling, traffic allocation and stopping/rollback policy design.
Machine LearningOnsite