Data Scientist Interview Questions

Showing 181–210 of 241 results

• SSpokeoMedium·Data Scientist
  Solve Logic Puzzles: Algorithms and Proofs Required

  This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Solve Logic Puzzles: Algorithms and Proofs Required states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Coding & AlgorithmsOnsite
• SquarepointMedium·Data Scientist
  Compute drawdown, profit, and coin change

  This question evaluates a candidate's ability to compute financial time-series metrics and apply algorithmic techniques such as array processing and optimization/dynamic programming to identify maximum drawdown and its indices.

  Coding & AlgorithmsTechnical Screen
• SquarepointMedium·Data Scientist
  Count Index Triplets With an Even Product Modulo a Given Number

  From a Squarepoint technical screen: count the triplets of distinct positions in an integer array whose three values have an even product, and return the count modulo a given number. It tests efficient counting on large inputs, parity with zero and negative values, and remembering to apply the required modulo.

  Coding & AlgorithmsTechnical Screen
• SquarepointMedium·Data Scientist
  Count Ways to Reach Step n With a Given Set of Step Sizes

  From a Squarepoint technical screen: count the ordered sequences of moves that climb exactly n stairs when every move uses a step size from a given set. It tests careful counting of ordered choices, targets that cannot be reached, and the interviewer's follow-up about reducing the extra space the solution uses.

  Coding & AlgorithmsTechnical Screen
• SquarepointMedium·Data Scientist
  Fewest Increment-All-but-One Moves to Make Array Values Equal

  From a Squarepoint technical screen: one move adds 1 to every element of an integer array except one chosen element, and you must find the fewest moves that make all elements equal. It tests reasoning about what each move really changes, along with negative values and answers beyond the 32-bit range.

  Coding & AlgorithmsTechnical Screen
• SquarepointMedium·Data Scientist
  Implement drawdown, single-trade profit, coin change

  This question evaluates a candidate's algorithmic problem-solving skills across array and time-series processing, greedy optimization, and dynamic programming, requiring implementation and complexity analysis of maximum drawdown, single-trade profit, and coin change problems within the Coding & Algorithms domain for a Data Scientist role.

  Coding & AlgorithmsTechnical Screen
• SquarepointHard·Data Scientist
  Maximize profit from one or many stock trades

  This question evaluates algorithmic problem-solving skills, particularly efficient array processing and profit-optimization across single-transaction and multiple-transaction variants, along with time and space complexity analysis.

  Coding & AlgorithmsTechnical Screen
• SquarepointMedium·Data Scientist
  Maximize revenue from inventory sales

  This question evaluates algorithmic problem-solving and optimization competencies focused on dynamic resource allocation, revenue maximization, and designing efficient solutions that scale with large n, m, and quantities.

  Coding & AlgorithmsOnline Assessment
• StripeMedium·Data Scientist
  Implement streaming per-user reservoir sampling

  This question evaluates a candidate's competency in streaming algorithms, per-user reservoir sampling, probabilistic reasoning and proof of correctness, concurrent/distributed merging, and engineering trade-offs for memory and amortized update efficiency.

  Coding & AlgorithmsTechnical Screen
• StripeEasy·Data Scientist
  Match payments to invoices by memo or amount

  This question evaluates string parsing, record linkage, and algorithmic matching skills for data reconciliation tasks, including handling messy memo text, exact amount matches, and tie-breaking by earliest due date.

  Coding & AlgorithmsTechnical Screen
• TTCSMedium·Data Scientist
  Find duplicates in a list efficiently

  This question evaluates a candidate's ability to design efficient algorithms for duplicate detection, occurrence counting, and preserving first-occurrence order while reasoning about time and space complexity across in-memory, in-place, and streaming data scenarios.

  Coding & AlgorithmsTechnical Screen
• The Trade DeskEasy·Data Scientist
  Implement monotonic-array linear interpolation

  This question evaluates proficiency with piecewise-linear interpolation on strictly increasing (monotonic) arrays, sound handling of out-of-range queries (error, clamp, extrapolate, or None/NaN), and efficient interval search over sorted data with a target of O(log n). It also probes real-world judgment about when each out-of-range policy is appropriate and which non-bisect strategies exist.

  Coding & AlgorithmsTechnical Screen
• ThumbtackMedium·Data Scientist
  Estimate Two Conditional Win Probabilities by Simulation

  This question tests practical coding ability in probabilistic simulation, requiring implementation of a Monte Carlo method to estimate conditional win probabilities under two decision strategies. It assesses a data scientist's skill in translating a classic probability scenario into working randomized code rather than relying on closed-form analysis.

  Coding & AlgorithmsTechnical Screen
• ThumbtackMedium·Data Scientist
  Implement min, mean, median robustly

  This question evaluates implementation skills in basic descriptive statistics (min, mean, median), numerical stability in online aggregation methods, robust handling of edge cases like None/NaN and extreme numeric ranges, and algorithmic complexity reasoning in the Coding & Algorithms domain for a Data Scientist role.

  Coding & AlgorithmsOnsite
• TikTokMedium·Data Scientist
  Analyze DFS, BFS, and A* trade-offs

  This question evaluates understanding of graph search algorithms, heuristic properties (admissibility and consistency), path optimality and time/space complexity, requiring application of BFS, uniform-cost search, A*, and DFS on a concrete weighted graph.

  Coding & AlgorithmsTechnical Screen
• TikTokMedium·Data Scientist
  Compute Averages of Unique Numbers in Dictionary Lists

  This question evaluates data manipulation and aggregation skills, focusing on handling duplicate values within collections and computing numerical summaries of list data.

  Coding & AlgorithmsOnsite
• TikTokMedium·Data Scientist
  Implement K-means and run two iterations

  This question evaluates understanding of k-means clustering concepts (k-means++ initialization, Lloyd iterations, and SSE) and proficiency in numerical implementation and vectorized array operations.

  Coding & AlgorithmsTechnical Screen
• TikTokMedium·Data Scientist
  Implement streaming SRM detector with late events

  This question evaluates proficiency in stateful stream processing, statistical anomaly detection for sample ratio mismatch, and scalable system design concerns such as deduplication, late/out-of-order event handling, real-time aggregation, chi-square testing with Yates correction, bot-rate mitigation, sharding, and replay validation.

  Coding & AlgorithmsHR Screen
• TikTokMedium·Data Scientist
  Maximize Distinct Purchases Within Budget Constraints

  This question evaluates understanding of selection and optimization under budget constraints, algorithmic efficiency, and the ability to implement correct logic for maximizing the number of distinct items purchased.

  Coding & AlgorithmsOnline Assessment
• TikTokMedium·Data Scientist
  Maximize products bought under budget

  This question evaluates algorithmic problem-solving skills including sorting, prefix-sum accumulation, binary search, greedy selection, careful tie-breaking for lexicographic order, and complexity analysis.

  Coding & AlgorithmsOnline Assessment
• TikTokMedium·Data Scientist
  Optimize Station Sequence for Maximum Car Output in Simulation

  This question evaluates a candidate's skills in scheduling and throughput optimization, including queue management and simulation-based performance analysis within constrained buffering and station sequencing.

  Coding & AlgorithmsOnsite
• Two SigmaHard·Data Scientist
  Add two integer strings using digit-adder

  This problem tests string manipulation, modular arithmetic, and the ability to manage carry-over logic manually to perform addition on integers that exceed the capacity of standard numeric data types.

  Coding & AlgorithmsTechnical ScreenString ManipulationTwo PointersArithmetic
• Two SigmaHard·Data Scientist
  Assign 2n Workers to Two Tasks to Minimize Total Time

  This question evaluates algorithmic problem-solving skills in combinatorial optimization and resource allocation, focusing on reasoning about cost differences when assigning 2n workers into two equal-sized tasks and belongs to the Coding & Algorithms domain.

  Coding & AlgorithmsTechnical Screen
• Two SigmaMedium·Data Scientist
  Compute Piecewise Linear Interpolation

  This question evaluates skills in algorithm design and numerical interpolation, including sorting and searching among 2D points, handling boundary cases for extrapolation, and computing linear interpolation accurately and efficiently.

  Coding & AlgorithmsOnline Assessment
• Two SigmaHard·Data Scientist
  Count Distinct Island Shapes in a Binary Grid

  This question evaluates a candidate's understanding of grid-based connected components and spatial equivalence, measuring competency in representing and distinguishing island shapes regardless of their location.

  Coding & AlgorithmsOnsite
• Two SigmaMedium·Data Scientist
  Evaluate Piecewise Linear Function

  This question tests the ability to efficiently search through sorted interval data and apply linear interpolation to compute the value of a continuous piecewise function at a specific input point.

  Coding & AlgorithmsOnline AssessmentBinary SearchInterpolationData Structures
• Two SigmaMedium·Data Scientist
  Evaluate a Piecewise Linear Function

  This question tests the ability to efficiently search through a sorted collection of coordinates and apply linear interpolation to compute values for a continuous piecewise function.

  Coding & AlgorithmsOnline AssessmentBinary SearchInterpolationGeometry
• Two SigmaMedium·Data Scientist
  Evaluate piecewise linear function at x

  This question evaluates competency in numerical interpolation and handling of piecewise linear functions, including locating the correct segment in a sorted sequence of points and managing out-of-range inputs.

  Coding & AlgorithmsOnline Assessment
• Two SigmaHard·Data Scientist
  Expected Number of Good Pairs in a Randomly Weighted Complete Graph

  This question evaluates probabilistic reasoning, combinatorics, and order-statistics intuition by asking for the expected count of mutual maximum-edge neighbors (good pairs) in an edge-weighted complete graph with i.i.d. continuous weights.

  Coding & AlgorithmsTechnical Screen
• Two SigmaEasy·Data Scientist
  Fill Missing Time-Series Values with Linear Interpolation (Duplicate Timestamps Allowed)

  This question evaluates a candidate's ability to perform time-series data cleaning and aggregation of duplicate timestamps, plus numerical linear interpolation and boundary value propagation, within the Coding & Algorithms domain.

  Coding & AlgorithmsOnline Assessment