Katkat

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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 4441–4470 of 4616 results

  • Walmart LabsHardSoftware Engineer
    Implement a Range Module with Add, Query, and Remove

    Design a data structure that tracks coverage of real numbers using half-open intervals, supporting dynamic additions, removals, and continuous coverage queries. This tests ordered data structure manipulation, interval merging/splitting invariants, and binary search.

    Coding & AlgorithmsTechnical Screenbinary-searchdesignintervals
  • Walmart LabsMediumSoftware Engineer
    Implement a Shape interface using OOP

    This problem tests your ability to design a robust object-oriented structure using interfaces and concrete class implementations, focusing on polymorphism and data encapsulation.

    Software Engineering FundamentalsTechnical ScreenOOPInterfacesPolymorphism
  • Walmart LabsMediumSoftware Engineer
    Implement lexicographically smallest Two Sum

    This question evaluates array manipulation, index-level reasoning, and algorithmic efficiency for locating pair sums under lexicographic tie-breaking, testing attention to ordering constraints and correct index selection.

    Coding & AlgorithmsTechnical Screen
  • Walmart LabsHardSoftware Engineer
    Shortest Talent-Covering Team Starting At Each Index

    Practice a sliding-window coding question where each start index needs the shortest contiguous team containing every talent type. This prompt targets hash map counts, two-pointer window management, and O(n) reasoning for large arrays.

    Coding & AlgorithmsTechnical Screen
  • Warner Bros DiscoveryMediumSoftware Engineer
    Design an ad content delivery system with A/B testing

    This question evaluates system-design and distributed-systems competency, specifically real-time ad serving, targeting and campaign data modeling, high-throughput event logging, and A/B testing/experimentation infrastructure including experiment assignment and metric computation.

    System DesignTechnical Screen
  • Warner Bros DiscoveryMediumSoftware Engineer
    Implement array rotations and CSV keyword search

    This question evaluates array manipulation and string parsing competencies, focusing on rotating arrays via modular index arithmetic and locating substring occurrences within a simple CSV while mapping each match to row, column, and character position.

    Coding & AlgorithmsTechnical Screen
  • WarpMediumSoftware Engineer
    Implement Terminal Tabs and Split Panels

    This question evaluates the ability to design and implement hierarchical data structures, model tree-based panel layouts, and perform precise serialization/deserialization of nested UI state.

    Coding & AlgorithmsTechnical Screen
  • WayfairHardSoftware Engineer
    Maximize the Product of Pair Distance and Minimum Value

    Tests optimal two-pointer and greedy reasoning to maximize a distance-weighted minimum value pair in linear time.

    Coding & AlgorithmsTechnical ScreenTwo PointersGreedyArrays
  • WayfairMediumApplied Scientist
    Set Bids for Search Advertising from Business Value

    Design search-ad bidding from expected business value, with budget pacing, delayed conversion feedback, auction assumptions, and incremental-profit evaluation.

    ML System DesignTechnical Screen
  • WaymoMediumFrontend Engineer
    Build a React naval board

    This question evaluates a candidate's ability to design frontend state and UI logic—specifically React component structure, state management, click-handling semantics, and derived sunk-detection logic for a Battleship-style board.

    Software Engineering FundamentalsTechnical Screen
  • WaymoMediumSoftware Engineer
    Build an Expression That Reaches a Target

    This problem tests your ability to use recursion with backtracking or dynamic programming to partition a sequence of numbers and apply operators to satisfy a target value.

    Coding & AlgorithmsTechnical ScreenRecursionBacktrackingMemoization
  • WaymoMediumData Scientist
    Compare Two Rare-Event Rates with Different Exposure

    Compare sparse event rates across unequal mileage using a two-sample Poisson framework, exact conditional testing, and honest uncertainty.

    Statistics & MathTechnical Screen
  • WaymoMediumSoftware Engineer
    Compute ETA between two map nodes

    This problem tests your ability to implement Dijkstra's algorithm to find the shortest path in a weighted directed graph representing a road network.

    Coding & AlgorithmsTechnical ScreenGraphsShortest PathDijkstra
  • WaymoMediumSoftware Engineer
    Compute Max Pooling Values and Coordinates

    This problem tests your ability to manipulate 2D arrays, manage sliding window bounds, and track metadata (indices) efficiently during a data transformation task.

    Coding & AlgorithmsTechnical ScreenArrays2D-GridSliding-Window
  • WaymoEasyData Scientist
    Compute probability match lasts 5 games

    This question evaluates understanding of discrete probability, sequential best-of-n match modeling, Monte Carlo simulation for probability estimation, and interval estimation for proportions.

    Statistics & MathTechnical Screen
  • WaymoHardSoftware Engineer
    Count Squares Formed by Segments

    Count distinct axis-aligned squares whose full sides are covered by horizontal and vertical integer-coordinate segments. Normalize and merge collinear coverage, avoid duplicate geometric squares, support overlapping segments and negative coordinates, and index interval coverage efficiently.

    Coding & AlgorithmsTechnical Screen
  • WaymoMediumMachine Learning Engineer
    Debug Tensor Conversion Bugs

    This question evaluates debugging and implementation-level skills in tensor and array manipulation, focusing on aliasing behavior, conversion between column lists and ndarrays, correct handling of non-divisible chunking, and writing tests for these issues.

    Coding & AlgorithmsTechnical Screen
  • WaymoMediumSoftware Engineer
    Decide If a Vehicle Is Ready to Go from Open/End Maintenance Events

    Given a vehicle maintenance log of open and end events with timestamps and maintenance types such as oil or brake, decide whether the vehicle is ready to go. The problem tests chronological event processing with a stable tie rule, per-type state tracking, and detecting unmatched ends, overlapping opens, and tasks left open.

    Coding & AlgorithmsTechnical Screen
  • WaymoMediumMachine Learning Engineer
    Design Large-Scale Inference Serving

    This question evaluates understanding of large-scale ML inference systems, assessing competencies in capacity planning, latency and tail-latency engineering, memory and bandwidth estimation, hardware selection (CPUs/GPUs/specialized accelerators), batching and caching trade-offs, and reliability concerns such as out-of-memory prevention and recovery. It is commonly asked to test practical system-design skills for production deployment by requiring back-of-the-envelope QPS and resource estimates and reasoning about operational trade-offs; this belongs to the ML system design category and emphasizes practical application over purely conceptual theory.

    ML System DesignTechnical Screen
  • WaymoMediumSoftware Engineer
    Design a Global Small-Image Caching Service

    This problem tests the ability to design a highly available, globally distributed caching layer that handles high-throughput small-image delivery while maintaining data consistency and resilience against origin failures.

    System DesignTechnical ScreenCachingDistributed SystemsLatency
  • WaymoMediumSoftware Engineer
    Design a Real-Time Player Matchmaking Service

    This problem tests the ability to design a distributed, low-latency matchmaking system capable of handling concurrent requests, state consistency, and efficient participant matching.

    System DesignTechnical ScreenDistributed SystemsConcurrencyCaching
  • WaymoMediumSoftware Engineer
    Design a System for a Vehicle Fleet Collecting Map Data for Autonomous Driving

    A system design interview question asking you to design the system that runs a vehicle fleet collecting sensor data for autonomous driving maps. It tests coverage and mission planning, offloading very large sensor logs, reliable ingestion, data quality checks, privacy, and storage at petabyte scale.

    System DesignTechnical Screen
  • WaymoMediumSoftware Engineer
    Design and Implement a Cross-System Object Tracker

    This problem tests your ability to design an efficient data structure for maintaining and merging temporal events associated with multiple system-generated IDs for the same physical object.

    Software Engineering FundamentalsTechnical ScreenDSUData StructuresSystem Design
  • WaymoMediumSite Reliability Engineer
    Determine Complete Interval Coverage

    This question evaluates understanding of interval coverage, streaming or online algorithms, and data structures for maintaining dynamic unions of intervals as points arrive.

    Coding & AlgorithmsTechnical Screen
  • WaymoEasyData 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
  • WaymoMediumData Scientist
    Estimate Event Rates from Unequal-Probability Samples

    Establish event rates from unequal sampling with inverse-probability weighting, exposure-aware denominators, and efficient stratified allocation.

    Statistics & MathTechnical Screen
  • WaymoEasyData Scientist
    Estimate total attendance from size-biased reservation sample

    This question evaluates understanding of size-biased sampling, selection bias correction, finite-population total estimation, and uncertainty quantification in survey sampling.

    Statistics & MathTechnical Screen
  • WaymoMediumData Scientist
    Evaluate a New Version in Simulation and Explain a Flat Live Result

    Compare model versions on paired simulation scenarios and diagnose why offline improvements may disappear in live rare-event evaluation.

    Analytics & ExperimentationTechnical Screen
  • WaymoMediumSoftware Engineer
    Expand Nested Repetition Expressions

    This problem tests your ability to parse nested patterns and handle recursion or stack-based state management to expand strings defined by repetition rules.

    Coding & AlgorithmsTechnical ScreenStringsRecursionStack
  • WaymoMediumSoftware Engineer
    Find Every Island in a Grid and Measure Its Boundary with Water

    A grid coding problem that asks you to find every island of land cells and report the length of each island's boundary with water, including enclosed lakes and grid edges. It tests grid traversal, connected components, careful edge counting, and deterministic output ordering.

    Coding & AlgorithmsTechnical Screen