Data Scientist Interview Questions

Showing 151–180 of 241 results

• PinterestMedium·Data Scientist
  Implement Jackknife and Random Choice

  Implement weighted random selection from scratch and compute delete-1 jackknife estimates of parameter bias and standard error for an arbitrary statistical estimator.

  Coding & AlgorithmsTechnical Screensamplingresamplingstatistics
• PinterestMedium·Data Scientist
  Implement LRUCache with O(1) Operations and Thread Safety

  This question evaluates a candidate's ability to implement a constant-time LRU cache and reason about thread-safety and concurrent access, testing data structure design and concurrency competencies in the Coding & Algorithms domain.

  Coding & AlgorithmsOnsite
• PinterestMedium·Data Scientist
  Implement and extend My Calendar III

  This question evaluates competency in designing and implementing efficient dynamic interval data structures, handling correctness for duplicate and nested intervals, extending APIs with cancellation and point queries, and performing rigorous worst-case time/space analysis and resource-adaptation.

  Coding & AlgorithmsTechnical Screen
• PinterestEasy·Data Scientist
  Implement np.random.choice

  This problem tests your ability to implement weighted random sampling from an array, focusing on probability distribution handling and efficient selection algorithms.

  Coding & AlgorithmsTechnical ScreenProbabilitySamplingAlgorithms
• PinterestMedium·Data Scientist
  Implement weighted random choice

  This problem tests your ability to implement efficient weighted random selection, specifically focusing on cumulative distribution functions and binary search to achieve optimal query performance.

  Coding & AlgorithmsTechnical ScreenAlgorithmsProbabilityBinary Search
• PinterestMedium·Data Scientist
  Maximize Non-Overlapping Task Scheduling Efficiency

  This question evaluates understanding of interval scheduling and resource optimization, focusing on reasoning about time intervals and conflict-free selection of tasks.

  Coding & AlgorithmsOnsite
• 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
  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
• Point72Easy·Data Scientist
  Find kth missing integer and redundant operations

  This paired question evaluates array and algorithmic skills — specifically order-statistics and missing-number reasoning for the k-th missing positive, and time-window aggregation with frequency tracking for detecting redundant log events — within the coding & algorithms domain.

  Coding & AlgorithmsOnline Assessment
• Point72Hard·Data Scientist
  Implement composition and mixin utilities

  This problem tests proficiency in functional composition, Python metaclass/decorator patterns, and custom serialization logic, focusing on handling flexible arguments and object introspection.

  Coding & AlgorithmsOnline AssessmentPythonFunctional ProgrammingSerialization
• 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
• 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
• 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
• RobloxEasy·Data Scientist
  Implement four DS coding tasks

  This multi-part question evaluates a data scientist's competencies in statistical inference (sample size and z-test calculations), causal inference and parallel-trends validation (difference-in-differences), Bayesian probability updating, and interpretable supervised learning feature importance, all framed as coding tasks.

  Coding & AlgorithmsOnline Assessment
• RobloxMedium·Data Scientist
  Implement streaming CTR with deduplication

  This question evaluates streaming data-processing and algorithmic design skills, specifically time-windowed aggregation, click deduplication, late-event handling, state management, and selection of data structures for per-campaign CTR computation.

  Coding & AlgorithmsTechnical Screen
• RobloxMedium·Data Scientist
  Optimize assembly-line scheduling with changeovers

  This question evaluates combinatorial optimization and scheduling competencies, specifically reasoning about NP-hardness, sequence-dependent setup times, precedence and downtime constraints, and designing exact and heuristic solvers for makespan minimization.

  Coding & AlgorithmsOnline Assessment
• RobloxMedium·Data Scientist
  Optimize bread-factory pipeline for max profit

  This question evaluates skills in combinatorial optimization, budgeted resource allocation, bottleneck throughput modeling, and algorithm design with cost amortization for maximizing profit under constraints.

  Coding & AlgorithmsOnsite
• SIG (Susquehanna)Medium·Data Scientist
  Compute bus-on-time and dice-sum probabilities

  This problem tests your ability to calculate probabilities involving continuous uniform distributions and discrete combinations of independent events.

  Coding & AlgorithmsHR ScreenProbabilityCombinatoricsUniform Distribution
• SSchonfeldMedium·Data Scientist
  Compute 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
• SSchonfeldMedium·Data Scientist
  Find 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
• ShopifyMedium·Data Scientist
  Calculate 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
• ShopifyMedium·Data Scientist
  Compute 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
• ShopifyMedium·Data Scientist
  Compute 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
• ShopifyMedium·Data Scientist
  Identify Pirate Themes Using Similarity Score Algorithm

  This question evaluates understanding of similarity scoring, set-based comparison of structured records, and practical data deduplication techniques commonly used in data science.

  Coding & AlgorithmsTechnical Screen
• ShopifyMedium·Data Scientist
  Implement Cosine Similarity Function for String Vectors

  This question evaluates understanding of vector-space similarity and text representation by asking for a cosine similarity computation over string-derived vectors, testing coding and algorithmic skills relevant to data science and text processing.

  Coding & AlgorithmsTechnical Screen
• ShopifyMedium·Data Scientist
  Implement an LRU Cache

  This question tests the ability to combine a hash map and a doubly linked list to achieve constant-time performance for cache operations.

  Coding & AlgorithmsTechnical ScreenHash MapDoubly Linked ListCache
• ShopifyEasy·Data Scientist
  Infer and justify non-trivial sequence patterns

  This question evaluates mathematical reasoning, sequence inference, and pattern-recognition competency by asking the solver to identify governing rules and justify missing terms across numeric sequences and a small grid.

  Coding & AlgorithmsTechnical Screen
• SnowflakeHard·Data Scientist
  Implement DFS with cycle detection and topo order

  This question evaluates mastery of graph algorithms—specifically depth-first search (both recursive and iterative), directed cycle detection, topological ordering, and discovery/finish timestamping—and falls under the Coding & Algorithms domain.

  Coding & AlgorithmsTechnical Screen
• SnowflakeMedium·Data Scientist
  Solve and optimize 3Sum and variants at scale

  This question evaluates algorithmic problem-solving skills in array processing, deduplication and combinatorial counting, external-memory and streaming algorithm design, and complexity analysis including integer overflow considerations.

  Coding & AlgorithmsOnsite