Data Scientist Interview Questions

Showing 91–120 of 241 results

• GGsaHard·Data Scientist
  Optimize Matrix-Chain Multiplication

  This problem tests your ability to solve a classic dynamic programming challenge, focusing on finding the optimal order of matrix multiplications to minimize the total number of scalar operations.

  Coding & AlgorithmsTechnical ScreenDynamic ProgrammingAlgorithmsOptimization
• Hudson River TradingMedium·Data Scientist
  Count Smaller Numbers with Only Zero and One in Base Four

  Count the number of positive integers strictly less than n whose base-4 representation consists only of the digits 0 and 1.

  Coding & AlgorithmsOnline AssessmentMathBit ManipulationDigit DP
• Hudson River TradingMedium·Data Scientist
  Count inversions in a permutation

  This question evaluates understanding of inversion counting in permutations, testing algorithmic problem-solving, complexity analysis, and data-structure reasoning about pairwise order relations.

  Coding & AlgorithmsTechnical Screen
• J.P. MorganMedium·Data Scientist
  Implement Integer Square Root

  This question evaluates numerical algorithm design and integer arithmetic competence, including robustness for edge cases and overflow handling, and is categorized in the Coding & Algorithms domain.

  Coding & AlgorithmsTechnical Screen
• J.P. MorganMedium·Data Scientist
  Implement KNN from Scratch

  This problem tests your ability to implement the K-Nearest Neighbors (KNN) algorithm from scratch, focusing on distance computation, sorting, and majority voting logic.

  Coding & AlgorithmsTechnical ScreenKNNSupervised LearningAlgorithms
• J.P. MorganMedium·Data Scientist
  Solve tiling, probability, and nested-radical puzzles

  This problem tests your ability to derive recurrence relations for combinatorial tiling, solve infinite series limits, and calculate exact probabilities using combinations.

  Coding & AlgorithmsOnsiteCombinatoricsDynamic ProgrammingProbability
• LLendingClubMedium·Data Scientist
  Determine If Two Numbers Sum to Target

  This question evaluates a candidate's basic algorithmic fluency in array processing and the ability to reason about pairwise sums using auxiliary data structures.

  Coding & AlgorithmsTechnical Screen
• LinkedInMedium·Data Scientist
  Find index with positive suffix sums

  This problem tests your ability to optimize array traversals using prefix or suffix sums, specifically evaluating your skill in calculating cumulative values efficiently in O(n) time.

  Coding & AlgorithmsTechnical ScreenArraysSuffix SumOptimization
• LinkedInEasy·Data Scientist
  How do you sample uniformly from an infinite stream?

  This question tests the implementation of Reservoir Sampling to maintain a uniform random sample of size k from a stream of unknown or infinite length.

  Coding & AlgorithmsTechnical ScreenAlgorithmsProbabilityStreaming
• LinkedInMedium·Data Scientist
  Implement fast sampling for weighted k-sided die

  This question evaluates understanding of probabilistic algorithm design, numerical stability, and efficient data-structure implementation for constant-time sampling from categorical distributions.

  Coding & AlgorithmsTechnical Screen
• LinkedInMedium·Data Scientist
  Implement stream random sampling in Python

  This question evaluates understanding of streaming algorithms, uniform random sampling, and probabilistic guarantees for maintaining a fixed-size sample from an unbounded data stream (reservoir-sampling concepts).

  Coding & AlgorithmsTechnical Screen
• LyftMedium·Data Scientist
  Optimize Driver Repositioning for Minimal Pickup Time

  This question evaluates spatial algorithms and real-time optimization for ride dispatch together with interval scheduling and capacity planning competencies, covering skills in computational geometry, routing, demand forecasting, and temporal overlap reasoning.

  Coding & AlgorithmsOnsite
• MetaMedium·Data Scientist
  Compute 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
• MetaMedium·Data Scientist
  Design robust group size limiting for calls

  This question evaluates distributed systems design, concurrency control, admission-control algorithms, and scalability under real-time and race-condition constraints.

  Coding & AlgorithmsTechnical Screen
• MetaMedium·Data Scientist
  Optimize Oculus Data Streaming with Bandwidth Constraints

  This question evaluates a candidate's ability in algorithm design and problem decomposition for array segmentation and interval coverage, focusing on reasoning about cumulative constraints for streaming data and geometric interval intersections.

  Coding & AlgorithmsOnsite
• MetaMedium·Data Scientist
  Optimize Travel Costs and Generate Rotational Symmetric Numbers

  This question evaluates algorithmic optimization and complexity-analysis skills by combining array-based time-dependent pricing for round-trip cost minimization with combinatorial generation of rotationally symmetric (strobogrammatic) k-digit numbers.

  Coding & AlgorithmsTechnical Screen
• MicrosoftHard·Data Scientist
  Implement lower_bound on unknown-size sorted array

  This question evaluates ability to design efficient search algorithms for unknown-length non-decreasing arrays accessed via a limited get(i) API, emphasizing correctness proof and tight query/time complexity bounds.

  Coding & AlgorithmsOnsite
• MicrosoftMedium·Data Scientist
  Implement rotated array binary search with duplicates

  This question evaluates algorithm design and analysis skills, focusing on binary-search variants, handling duplicates in rotated non-decreasing arrays, rotation-index reasoning, and rigorous edge-case analysis; domain: Coding & Algorithms, specifically search algorithms and array manipulation.

  Coding & AlgorithmsOnsite
• MicrosoftMedium·Data Scientist
  Print Org Chart by Level

  This problem tests your ability to model a tree structure from flat parent-child relations and perform a level-order traversal to format hierarchical data.

  Coding & AlgorithmsTechnical ScreenTreesBFSGraphs
• MicrosoftEasy·Data Scientist
  Traverse org chart level by level

  This problem tests your ability to reconstruct a tree structure from a flat list of relationships and perform a breadth-first search (BFS) to group employees by their organizational depth.

  Coding & AlgorithmsTechnical ScreenTreesBFSGraphs
• MicrosoftEasy·Data Scientist
  Write an average-income function

  This problem tests your ability to clean and aggregate numerical data using Python, specifically handling missing values (None/NaN) and calculating a clean arithmetic mean.

  Coding & AlgorithmsTechnical ScreenData CleaningPythonStatistics
• Morgan StanleyEasy·Data Scientist
  Compute win probability in coin-toss game

  This question evaluates understanding of probability theory and stochastic processes, focusing on win probability in an alternating coin-toss game and reasoning about pattern occurrence and stopping times in random sequences.

  Coding & AlgorithmsTechnical Screen
• Morgan StanleyMedium·Data Scientist
  Implement Factorial and Squares

  A Morgan Stanley data scientist HR-screen live-coding warm-up: implement Python `factorial(n)` (iteratively, then explain the recursive version) and `squares(n)` returning the squares of the first n integers. Evaluates clean Python, the iteration-vs-recursion trade-off, time and space complexity analysis, input validation, and edge cases like n = 0 and negative input.

  Coding & AlgorithmsHR Screen
• NVIDIAHard·Data Scientist
  Design and explain robust web APIs for ML inference

  This question evaluates a candidate's proficiency in designing HTTP REST APIs for ML inference, including API endpoints, versioning, idempotency, request/response schemas, authentication/authorization, rate limiting, observability, and backward-compatibility policies, and it falls under the Coding & Algorithms domain for a data scientist role.

  Coding & AlgorithmsHR Screen
• NVIDIAHard·Data Scientist
  Implement CUDA-tiled matrix multiplication and explain architecture

  This question evaluates a candidate's competency in CUDA GPU programming, parallel algorithms, and performance engineering for FP32 matrix multiplication, covering tiling strategies, memory hierarchy (global/shared/register), synchronization, numerical precision, and occupancy/resource analysis.

  Coding & AlgorithmsHR Screen
• NVIDIAHard·Data Scientist
  Optimize CUDA GEMM with tiling and coalescing

  This question evaluates proficiency in GPU programming and performance optimization, assessing understanding of the CUDA execution model, memory hierarchy and bank conflicts, occupancy limits, and practical kernel design concerns for single-precision GEMM including tiling, coalescing, vectorized memory accesses and benchmarking.

  Coding & AlgorithmsHR Screen
• NVIDIAHard·Data Scientist
  Reverse linked lists, including k-group

  This question evaluates understanding of linked list manipulation including pointer operations, in-place reversal techniques, recursion and stack-depth considerations, cycle detection, and time/space complexity analysis.

  Coding & AlgorithmsHR Screen
• NetflixMedium·Data Scientist
  Identify Longest Consecutive Incrementing Watch-Time Sequence

  This question evaluates a candidate's ability to design and analyze efficient algorithms for detecting longest consecutive incrementing sequences in unsorted integer arrays, testing understanding of appropriate data structures and time/space complexity trade-offs.

  Coding & AlgorithmsOnsite
• NetflixMedium·Data Scientist
  Implement longest increasing subarray with one deletion

  This question evaluates proficiency in array algorithms and algorithmic optimization, focusing on handling boundary cases, reconstructing index ranges, and meeting strict O(n) time and O(1) extra-space constraints.

  Coding & AlgorithmsOnsite
• OpenAIMedium·Data Scientist
  Identify Bugs in Python Script for User Assignment

  This question evaluates a candidate's ability to detect bugs and data-quality risks in a Python script, testing competencies in code review, reproducible randomization, idempotency, logging, duplicate-exposure safeguards, and safe experiment-assignment logic.

  Coding & AlgorithmsOnline Assessment