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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 151–180 of 1971 results
- AmazonMediumData ScientistImplement a high-throughput web crawler safely
This question evaluates competency in concurrent systems, scalable data ingestion, and algorithmic design for a high-throughput web crawler, covering URL normalization, deduplication, per-host rate limiting, fault-tolerant checkpointing, and bounded-memory queueing.
Coding & AlgorithmsTechnical Screen - AmazonMediumData ScientistImplement and Analyze 'Merge k Sorted Lists' Algorithm
This question evaluates algorithm design skills and complexity analysis for merging multiple sorted sequences, measuring proficiency with appropriate data structures, time-space trade-offs, and correctness reasoning.
Coding & AlgorithmsOnsite - AmazonMediumData ScientistImplement list overlap and dense-ranked word frequencies
This question evaluates a data scientist's ability to implement efficient multiset intersection and streaming top-k word-frequency computations, covering duplicate-aware counting, dense-ranking, Unicode handling, and strict time/space constraints.
Coding & AlgorithmsOnsite - AmazonMediumData ScientistImplement streaming k-way merge with constraints
This question evaluates competence in streaming algorithms and resource-constrained algorithm design, specifically implementing a k-way merge over blocking, potentially unbounded integer iterators while preserving stable duplicates and reasoning about time and O(k) space complexity.
Coding & AlgorithmsOnsite - AmazonMediumData ScientistList Top Customers and Monthly Order Counts in SQL
This question evaluates a candidate's ability to perform SQL aggregation, grouping, top‑N selection, and date-based summarization to compute customer spend and chronological monthly order counts.
Data Manipulation (SQL/Python)Technical Screen - AmazonMediumData ScientistMitigate Data Mistakes and Improve Team Efficiency
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Mitigate Data Mistakes and Improve Team Efficiency states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - AmazonMediumData ScientistNavigate Crises and Sustain Team Morale Under Pressure
Navigate Crises and Sustain Team Morale Under Pressure evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - AmazonMediumData ScientistOptimize Email Strategy for New Prime Video Series Launch
Evaluates email targeting and ranking strategy for a new Prime Video series launch. Strong answers cover data needs, cold start, ranking models, offline metrics, A/B testing, guardrails, and model selection.
Machine LearningOnsite - AmazonMediumData ScientistOptimize Predictive Analytics: Feature Engineering to Model Evaluation
Evaluates end-to-end predictive analytics project communication for a technical data-science interview. Strong answers cover business objectives, data, leakage controls, features, models, evaluation, errors, and impact.
Machine LearningTechnical Screen - AmazonMediumData ScientistOptimize XGBoost for Predicting Marketing Outcomes
Optimize XGBoost for Predicting Marketing Outcomes evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningOnsite - AmazonHardData ScientistPlan and analyze an A/B test
This question tests the ability to design a statistically rigorous A/B test by accounting for clustered randomization, sequential testing boundaries, and multiple comparison corrections.
Statistics & MathTechnical ScreenExperimental DesignPower AnalysisClustered Data - AmazonMediumData ScientistPrioritize Tasks and Respond to Coworker Concerns
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Prioritize Tasks and Respond to Coworker Concerns states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnline Assessment - AmazonHardData ScientistPrioritize a new warehouse proposal with data
This question evaluates demand forecasting, network optimization, five-year NPV financial modeling, experiment and quasi-experiment design for incrementality estimation, sensitivity analysis, and stakeholder communication within the analytics & experimentation domain for data science roles focused on warehouse/fulfillment center decisions.
Analytics & ExperimentationTechnical Screen - AmazonMediumData ScientistProfile and visualize an unfamiliar dataset
This question evaluates a data scientist's competency in exploratory data analysis, data quality assessment, time-series aggregation, visualization design, and concise stakeholder communication when working with an undocumented events-plus-purchases CSV.
Analytics & ExperimentationTechnical Screen - AmazonHardData ScientistQuantify build-vs-buy training decision
This question evaluates proficiency in quantitative decision analysis, causal inference for experimentation, KPI definition, and risk‑adjusted financial modeling within the Analytics & Experimentation domain, assessing skills relevant for a Data Scientist making operational trade‑offs.
Analytics & ExperimentationOnline Assessment - AmazonMediumData ScientistResolve Conflicts Between Data Findings and Team Opinions
Resolve Conflicts Between Data Findings and Team Opinions evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - AmazonMediumData ScientistResolve Team Conflicts and Deliver Beyond Project Scope
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Resolve Team Conflicts and Deliver Beyond Project Scope states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipTechnical Screen - AmazonMediumData ScientistResolve a team conflict decisively
The question evaluates conflict-resolution, decisive leadership, stakeholder management, evidence-based decision-making, communication under time pressure, and the ability to enforce delivery timelines and run post-mortems within a Data Scientist role.
Behavioral & LeadershipTechnical Screen - AmazonMediumData ScientistRespond to Difficult Critical Feedback
Practice discussing difficult feedback with a concrete example, an observable behavior change, and evidence of improvement.
Behavioral & LeadershipTechnical Screen - AmazonHardData ScientistRoot-cause an incident and drive consensus
This question evaluates root-cause analysis, incident management, cross-functional stakeholder coordination, and quantitative diagnostic reasoning in the context of a sudden drop in voice checkout conversion, testing product analytics, ML-driven user flows, and operational reliability within the Behavioral & Leadership category.
Behavioral & LeadershipOnsite - AmazonMediumData ScientistSelect Top Customers Using Transaction Data Filters
This question evaluates a candidate's ability to perform data aggregation, filtering, ranking, and deterministic tie-breaking on transactional datasets, assessing skills in Data Manipulation (SQL/Python).
Data Manipulation (SQL/Python)Technical Screen - AmazonMediumData ScientistSolve Algorithmic Challenges in Online Coding Assessments
This question evaluates proficiency in fundamental algorithmic problem-solving, specifically array manipulation, string processing, and the use of basic data structures along with performance and complexity reasoning.
Coding & AlgorithmsTechnical Screen - AmazonMediumData ScientistSolve Search Insert Position Using Binary Search
This question evaluates proficiency in binary search, algorithmic implementation on sorted arrays, and understanding of time complexity and index management.
Coding & AlgorithmsTechnical Screen - AmazonMediumData ScientistSolve stock, BFS path, and merge intervals
This question evaluates algorithmic problem solving across array scanning, BFS-based constrained shortest-path selection, and interval merging, with emphasis on time/space complexity reasoning, correctness proofs, and thorough edge-case handling. It is commonly asked to assess efficiency guarantees (e.g.
Coding & AlgorithmsTechnical Screen - AmazonHardData ScientistSolve subset-count and kth-factor problems
This question evaluates algorithm design and analysis skills, including selection under sum constraints with negatives and zeros, streaming and query-preprocessing strategies for repeated budgets, and number-theoretic factor enumeration for large N, all within the Coding & Algorithms domain.
Coding & AlgorithmsOnline Assessment - AmazonEasyData ScientistSolve two string DP/hash problems
This question set evaluates string-processing and algorithmic problem-solving skills, including encoding and transformation for unique representations and dynamic programming, memoization, and backtracking for enumerating all valid segmentations.
Coding & AlgorithmsTechnical Screen - AmazonMediumData ScientistSolve two-sum variants at scale
This question evaluates array and hashing algorithms, pair-sum reasoning including duplicate handling and lexicographic minimality, streaming and external-memory algorithm design, trade-offs in time/space complexity, and extension to three-sum with deduplication.
Coding & AlgorithmsOnsite - AmazonMediumData ScientistTransform Customer Feedback into Valuable Product Enhancements
Transform Customer Feedback into Valuable Product Enhancements evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - AmazonMediumData ScientistTransform event logs with subscription windows in pandas
This question evaluates a candidate's competency in time-based event attribution and temporal interval manipulation using pandas, covering interval merging, subscription-aligned revenue aggregation, anomaly flagging, and handling edge cases like overlapping or back-to-back subscriptions.
Data Manipulation (SQL/Python)Onsite - AmazonMediumData ScientistUnderstand SQL: DELETE vs TRUNCATE, VIEW vs TABLE, CROSS JOIN
This question evaluates a candidate's understanding of core SQL concepts and data-manipulation competencies, covering the behavior of data-deletion operations, distinctions between logical and physical data structures, and join semantics.
Data Manipulation (SQL/Python)Technical Screen