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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
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- 11
- Topics
- 8
- Languages
Showing 1561–1590 of 1971 results
- SIG (Susquehanna)EasyData ScientistFind Expected Spins Until Two Regions Appear
This problem tests knowledge of expected value and geometric distributions by calculating the expected number of trials to observe two distinct outcomes from a discrete probability distribution.
Statistics & MathOnline AssessmentProbabilityExpected ValueGeometric Distribution - SIG (Susquehanna)EasyData ScientistFind a Green Triangle's Weight in a Balanced Mobile
Solve a nested balanced-mobile puzzle and determine the green triangle's weight from a 160-pound total. The worked derivation uses an explicit equal-arm, massless-bar assumption, propagates whole-submobile weights upward, and explains why the left branch alone fixes the answer at 10 pounds.
Statistics & MathOnline Assessment - SIG (Susquehanna)MediumData ScientistFind probability of overlapping blooms
This question evaluates understanding of probability theory, specifically reasoning about continuous uniform distributions, geometric probability, and the likelihood of overlap between random time intervals within a fixed horizon.
Statistics & MathOnline Assessment - SIG (Susquehanna)EasyData ScientistFind the Expected Number of Consecutive Chosen Pairs
Calculate the expected number of consecutive pairs in a uniformly chosen subset of integers using indicator variables and linearity of expectation.
Statistics & MathOnline Assessmentprobabilitycombinatoricsexpected-value - SIG (Susquehanna)EasyData ScientistFind the Probability Two Muffins Are Sufficient
This problem tests binomial probability distributions and the cumulative probability of independent discrete events.
Statistics & MathOnline AssessmentProbabilityBinomial DistributionStatistics - SIG (Susquehanna)EasyData ScientistFind the Success Probability of Bold Betting
Calculate the chance of reaching five tokens before ruin under a bold, state-dependent betting rule. The solution enumerates the transitions, sets absorbing boundaries, solves the four-state recurrence for win probability one-third, and obtains 15/77 from an initial fortune of two.
Statistics & MathOnline Assessment - SIG (Susquehanna)EasyData ScientistInfer posterior after losing pick
This question evaluates a candidate's understanding of conditional probability and posterior inference, assessing the ability to update probability estimates after observing that a chosen option did not occur.
Statistics & MathOnline Assessment - SIG (Susquehanna)EasyData ScientistResolve Two Knights-and-Knaves Statements
This question tests logical deduction and systematic case analysis under binary truth constraints.
Statistics & MathOnline AssessmentLogicPuzzlesDiscrete Math - SIG (Susquehanna)EasyData ScientistSolve Barn Animal Counts from Total Legs
Tests setting up and solving a system of linear equations from verbal constraints using substitution to determine integer entity counts.
Statistics & MathOnline Assessmentmathalgebraquantitative-reasoning - SIG (Susquehanna)EasyData ScientistSolve animals-and-legs count
This question evaluates a candidate's ability to translate a word problem into a system of linear equations and perform basic algebraic manipulation and arithmetic to determine unknown quantities.
Statistics & MathOnline Assessment - SIG (Susquehanna)MediumData ScientistSolve relative-truth cat puzzle
This question evaluates logical deduction, constraint satisfaction, and quantitative manipulation of percentages and averages within a relative truth/lie framework, and is categorized under Statistics & Math and discrete logic puzzles.
Statistics & MathOnline Assessment - SIG (Susquehanna)EasyData ScientistUse Bayes for factory identification
This question evaluates understanding of Bayesian inference and conditional probability by asking for the posterior probability that two observed black widgets originated from a specific factory.
Statistics & MathOnline Assessment - SamsungMediumData ScientistEstimate laptops in an office
This question evaluates back-of-the-envelope estimation skills, quantitative reasoning, and the ability to state and justify assumptions when modeling real-world counts like devices.
Statistics & MathHR Screen - SamsungMediumData ScientistPlan parking demand for a retail store
This question evaluates demand forecasting, capacity planning, causal inference, and experimental-design competencies within data science, focusing on translating business objectives into measurable metrics such as peak occupancy, overflow rate, lost visits, and return on investment.
Analytics & ExperimentationHR Screen - SchonfeldMediumData ScientistCompute probability last passenger gets own seat
This question evaluates a candidate's understanding of probability theory, combinatorics, and reasoning about sequential random processes, with emphasis on symmetry and conditional dependence.
Coding & AlgorithmsOnline Assessment - SchonfeldMediumData ScientistFind smallest N for 5-and-21 sums
This question evaluates understanding of integer linear combinations and elementary number theory, framed as a Frobenius coin problem that examines representability using non-negative multiples of 5 and 21.
Coding & AlgorithmsOnline Assessment - ShopifyMediumData ScientistAnalyze Causes of November and June Shopify Traffic Spikes
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 Analyze Causes of November and June Shopify Traffic Spikes states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationOnsite - ShopifyMediumData ScientistAnalyze Pirate Theme Usage Growth Over Time
This question evaluates a candidate's ability to perform SQL-based data manipulation and time-series analysis, emphasizing joins, aggregation, time-bucketing, and definition of growth metrics to measure feature adoption.
Data Manipulation (SQL/Python)Technical Screen - ShopifyMediumData ScientistAnalyze Pirated Theme Usage
Calculate monthly metrics on unlicensed theme usage and lost revenue by evaluating temporal interval overlaps between installation lifespans and calendar months.
Data Manipulation (SQL/Python)Technical ScreenSQLPandasInterval Overlap - ShopifyMediumData ScientistAnalyze Pirated Theme Usage Impact
This question evaluates a candidate's ability to perform data manipulation and analytics with SQL and Python to detect license compliance, construct month-level time windows, and quantify revenue impact from pirated theme usage.
Data Manipulation (SQL/Python)Technical Screen - ShopifyMediumData ScientistAnalyze Trends to Optimize Pirate-Theme Product Strategy
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 Analyze Trends to Optimize Pirate-Theme Product Strategy states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Analytics & ExperimentationTechnical Screen - ShopifyEasyData ScientistAnswer Product DS HR Screen
This prompt evaluates behavioral and leadership competencies for a product data scientist role, including product thinking, stakeholder management, communication, motivation, team composition and dynamics, and the ability to articulate business impact and role scope.
Behavioral & LeadershipHR Screen - ShopifyMediumData ScientistAssess Candidate's Remote Collaboration and Technical Proficiency
Evaluates remote cross-functional collaboration and technical proficiency for a data-science role. Strong answers cover challenging projects, stakeholder rituals, async artifacts, tool stack, reproducibility, and quantified impact.
Behavioral & LeadershipOnsite - ShopifyMediumData ScientistAssess and push back on ideology-heavy interviews
This question evaluates a candidate's competency in cultural fit assessment, evidence-backed critique, concise written and verbal communication, prioritization under time pressure, and the ability to design escalation and interview strategies.
Behavioral & LeadershipTechnical Screen - ShopifyMediumData ScientistCalculate Jaccard Similarity Score for Two String Lists
This question evaluates understanding of similarity metrics and competency in comparing string collections, reflecting knowledge of set-theoretic concepts and manipulation of collection data structures used in data processing.
Coding & AlgorithmsOnsite - ShopifyMediumData ScientistCalculate Week-over-Week Revenue Change Using SQL
This question evaluates proficiency in SQL time-series aggregation, weekly grouping, and prior-period comparison for calculating percentage changes in revenue.
Data Manipulation (SQL/Python)Technical Screen - ShopifyMediumData ScientistCompute Jaccard Similarity for Lists
This question evaluates understanding of Jaccard similarity and set-based operations, assessing competency in deduplicating lists, precise string comparisons (case-sensitivity and whitespace), and handling edge cases.
Coding & AlgorithmsTechnical Screen - ShopifyMediumData ScientistCompute Theme Similarity
This question tests the ability to implement a set-based similarity metric, specifically the Jaccard index, to compare collections of theme-related features.
Coding & AlgorithmsTechnical ScreenData StructuresAlgorithmsSets - ShopifyEasyData ScientistDeep dive a technical project and its impact
This question evaluates a data scientist's ability to lead and execute end-to-end technical projects, including problem framing, data sourcing and quality, modeling and experimentation, deployment and monitoring, and quantifying business impact.
Behavioral & LeadershipTechnical Screen - ShopifyMediumData ScientistDescribe Your Professional Growth and Key Learning Experiences
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Describe Your Professional Growth and Key Learning Experiences states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen