Data Scientist Interview Questions

Showing 211–240 of 241 results

• Two SigmaHard·Data Scientist
  Implement Univariate Linear Regression with Ordinary Least Squares

  This question evaluates understanding of univariate linear regression and the ordinary least squares (OLS) closed-form estimator, probing competencies in basic statistical estimation, interpretation of slope and intercept, numerical stability, and floating-point arithmetic.

  Coding & AlgorithmsOnsite
• Two SigmaMedium·Data Scientist
  Implement merge sort and largest 1-rectangle

  This question evaluates proficiency in implementing and analyzing classic algorithms, specifically merge sort for array sorting and techniques for computing the largest all-ones rectangular submatrix in a binary matrix, testing algorithmic thinking, data structure manipulation, and time/space complexity reasoning.

  Coding & AlgorithmsTechnical Screen
• Two SigmaEasy·Data Scientist
  Match readings with latest same-city humidity

  This question evaluates the ability to align and join time-ordered sensor data by key, testing skills in time-series merging, per-key state management, and handling absent matches.

  Coding & AlgorithmsTechnical Screen
• Two SigmaHard·Data Scientist
  Maximum-Product Simple Path in a Complete Directed Graph

  This question evaluates skills in graph algorithms, multiplicative path optimization, and combinatorial dynamic programming, testing competency in reasoning about simple paths and product-based scoring in directed weighted graphs.

  Coding & AlgorithmsOnsite
• Two SigmaHard·Data Scientist
  Merge Two Sorted Lists

  This problem tests your ability to manipulate linked list pointers to merge two sorted sequences efficiently without allocating extra space for new nodes.

  Coding & AlgorithmsTechnical ScreenLinked ListsPointersRecursion
• Two SigmaHard·Data Scientist
  Merge two sorted linked lists

  This problem tests your ability to manipulate linked list pointers to merge two sorted structures in-place, focusing on space optimization and handling edge cases.

  Coding & AlgorithmsTechnical ScreenLinked ListsPointersIn-place
• Two SigmaMedium·Data Scientist
  Return sorted values after quadratic transform

  This problem tests your ability to efficiently transform elements in a sorted array using a quadratic function and merge them back into a single sorted array in linear time.

  Coding & AlgorithmsTechnical ScreenArraysTwo PointersSorting
• UberMedium·Data Scientist
  Can one car serve all riders?

  This problem tests your ability to determine if a single resource (a car) can accommodate a series of scheduled tasks without overlap, requiring efficient sorting and comparison techniques.

  Coding & AlgorithmsTechnical ScreenSortingIntervalsGreedy
• UberMedium·Data Scientist
  Compute CDF from a PDF Function

  This problem tests your understanding of numerical integration techniques (specifically the trapezoidal rule) and your ability to implement a functional mapping of a continuous probability density function (PDF) into a discrete cumulative distribution function (CDF).

  Coding & AlgorithmsTechnical ScreenNumerical MethodsProbabilityIntegration
• UberMedium·Data Scientist
  Compute maximum concurrent trips from intervals

  This question evaluates a candidate's skill in designing efficient algorithms for interval overlap counting, including event ordering, handling half-open interval edge cases, and reasoning about concurrent activity timing.

  Coding & AlgorithmsTechnical Screen
• UberMedium·Data Scientist
  Compute square root to 1 decimal

  This question evaluates a candidate's understanding of numerical methods, floating-point precision, and implementation of approximate functions when producing a square root rounded to one decimal place.

  Coding & AlgorithmsTechnical Screen
• UberMedium·Data Scientist
  Convert a PDF to a CDF

  This question evaluates understanding of probability theory, numerical methods, and algorithmic implementation for converting probability density functions into cumulative distribution functions, addressing analytic versus sampled PDFs along with support, normalization, and monotonicity requirements.

  Coding & AlgorithmsTechnical Screen
• UberMedium·Data Scientist
  Design airport dispatch with ETA uncertainty

  This question evaluates proficiency in online algorithm design under uncertainty, stochastic modeling of ETAs, multi-objective optimization for resource allocation, and streaming data handling relevant to dispatch systems.

  Coding & AlgorithmsTechnical Screen
• UberMedium·Data Scientist
  Find the Next Larger Palindrome

  This question evaluates proficiency in numeric and string manipulation, algorithmic thinking, and edge-case reasoning related to palindromic number generation.

  Coding & AlgorithmsOnsite
• UberMedium·Data Scientist
  Implement FizzBuzz

  This problem tests foundational programming skills by requiring the implementation of conditional logic and string manipulation based on modular arithmetic patterns.

  Coding & AlgorithmsOnsiteAlgorithmsControl FlowStrings
• UberMedium·Data Scientist
  Implement weighted sampling without replacement

  This question evaluates a candidate's ability to design numerically stable, streaming weighted-sampling methods and tests competencies in randomized algorithms, probability, numerical analysis, and memory/time trade-offs.

  Coding & AlgorithmsTechnical Screen
• UberMedium·Data Scientist
  Move zeros to front

  This problem tests your ability to manipulate array indices in-place to reorder elements according to a specific condition while maintaining relative stability.

  Coding & AlgorithmsTechnical ScreenArraysTwo-PointersIn-place
• UpstartMedium·Data Scientist
  Design Algorithm for Longest Substring with K Distinct Characters

  This question evaluates proficiency in string-processing and sliding-window algorithm patterns, assessing competency in designing efficient solutions and managing data structures to track distinct elements and reason about time and space complexity.

  Coding & AlgorithmsOnsite
• UpstartEasy·Data Scientist
  Implement factorial and count trailing zeros

  This question evaluates understanding of factorial computation and algorithmic techniques, including iterative versus recursive approaches, handling large integers and recursion constraints, and efficient counting of trailing zeros via number-theoretic reasoning.

  Coding & AlgorithmsOnsite
• Virtu FinancialMedium·Data Scientist
  Implement Connect Four Winner Detection

  This question evaluates the ability to design and implement game-state logic for a Connect Four-style board, covering board data structures, coordinate and boundary handling, gravity-based token placement, and efficient pattern detection for consecutive tokens in the Coding & Algorithms domain.

  Coding & AlgorithmsTechnical Screen
• Virtu FinancialMedium·Data Scientist
  Maximize Points by Buying Cost-Multiplier Cards

  This problem tests your ability to determine an optimal ordering strategy and apply dynamic programming to maximize a cumulative score subject to specific operations.

  Coding & AlgorithmsTechnical ScreenDynamic ProgrammingGreedyOptimization
• Walmart LabsMedium·Data Scientist
  Find Index Pairs of Matching Elements in Arrays

  This question evaluates the ability to work with sorted arrays, index mapping, duplicate handling, and reasoning about correctness and algorithmic complexity.

  Coding & AlgorithmsOnsite
• WaymoEasy·Data Scientist
  Determine earliest collision among moving cars

  This question evaluates proficiency in kinematics, computational geometry, numerical root-finding, and scalable algorithm design for collision detection among moving objects, including attention to numerical precision and overlapping trajectories.

  Coding & AlgorithmsTechnical Screen
• WaymoMedium·Data Scientist
  Implement Safe Average Function

  This question evaluates proficiency with basic programming fundamentals including numeric computation, handling edge cases such as empty inputs, input immutability, and data type consistency.

  Coding & AlgorithmsOnline Assessment
• WaymoEasy·Data Scientist
  Implement nested template string substitution

  This problem tests your ability to handle recursive data structures and string parsing by expanding nested placeholders within a template string while identifying potential circular dependencies.

  Coding & AlgorithmsOnsiteRecursionString ProcessingMemoization
• WaymoMedium·Data Scientist
  Sample Points Uniformly from a Unit Disk

  Derive uniform random sampling inside a unit disk, explain the radial distribution, and compare a polar sampler with rejection sampling.

  Coding & AlgorithmsTechnical Screen
• YahooMedium·Data Scientist
  Merge words by head-tail chaining

  This question evaluates graph-theoretic reasoning and string-manipulation skills, focusing on the ability to reason about ordering constraints, edge cases like self-loops and multiple identical relationships, and traversal over relationships between items.

  Coding & AlgorithmsTechnical Screen
• YahooMedium·Data Scientist
  Solve Data Structure Challenges with Python Algorithms

  This question evaluates proficiency in fundamental data structure manipulation and string-processing algorithms, specifically preserving insertion order during list deduplication and performing iterative overlap-based word merging.

  Coding & AlgorithmsTechnical Screen
• YYelpEasy·Data Scientist
  Return Integers in Descending Ranked Order

  This problem tests the ability to manipulate lists and sort data while maintaining the relative order of duplicate elements using common programming patterns.

  Coding & AlgorithmsTechnical ScreenSortingArraysAlgorithms
• ZAZest AIHard·Data Scientist
  Compute tree depth and meeting rooms

  This question evaluates skills in tree traversal and recursion for computing maximum depth of a binary tree, alongside interval scheduling and resource allocation for determining the minimum number of meeting rooms, testing reasoning about data structures such as trees and interval endpoints.

  Coding & AlgorithmsOnsite