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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.
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Showing 9061–9090 of 9403 results
- Walmart LabsEasyMachine Learning EngineerDesign an item category prediction system
This question tests the ability to design an end-to-end classification system for assigning retail items into a hierarchical category structure, focusing on feature selection, model architecture, and production deployment.
ML System DesignOnsiteClassificationNLPMulti-modal - Walmart LabsHardSoftware EngineerDesign and Implement an In-Memory Job Scheduler for Delayed Jobs
Design and implement an in-memory job scheduler that runs submitted jobs after a delay and supports cancellation and shutdown. It tests choosing a structure ordered by due time, thread-safe coordination without busy waiting, worker concurrency, failure isolation and the trade-offs of recurring or persistent jobs.
Software Engineering FundamentalsOnsite - Walmart LabsMediumData ScientistFind 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 - Walmart LabsEasyMachine Learning EngineerFind first non-repeating character
This problem tests your ability to use hash maps or frequency arrays to achieve optimal time complexity when processing character streams or strings.
Coding & AlgorithmsOnsiteStringsHash MapFrequency Array - Walmart LabsMediumSoftware EngineerFind shared courses between student pairs
This problem tests your ability to efficiently map relationships and compute intersections between multiple sets to identify commonalities across pairs.
Coding & AlgorithmsTechnical ScreenHash MapSetData Structures - Walmart LabsEasySoftware EngineerFind the Longest Even-Length Word
Tests string tokenization, linear scanning, tie-breaking logic, and handling of edge cases such as absent matches or irregular whitespace.
Coding & AlgorithmsTechnical ScreenStringsAlgorithmsWalmart - Walmart LabsHardSoftware EngineerFind the Single Repeated Value Among n + 1 Integers Drawn from 1 to n
Given an array of n + 1 integers whose values all lie between 1 and n, return the one value that repeats, possibly several times. The challenge is solving it without modifying the array and with constant extra memory, which rules out sorting, hash sets and counting arrays.
Coding & AlgorithmsOnsite - Walmart LabsEasySoftware EngineerHandle conflict and motivate engineering teams
This question evaluates leadership competencies including conflict resolution, stakeholder management, and team motivation, emphasizing interpersonal decision-making and balancing technical quality with timelines.
Behavioral & LeadershipOnsite - Walmart LabsHardSoftware EngineerImplement 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 EngineerImplement 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 EngineerImplement 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 LabsMediumSoftware EngineerMaximum Sum of Non-Adjacent Values in a Row
A coding problem that asks for the largest total obtainable from a row of non-negative values when no two chosen positions may be adjacent. It tests reasoning about take-or-skip choices, edge cases such as empty and single-element rows, and a solution fast enough for rows of up to 100,000 values.
Coding & AlgorithmsOnline Assessment - Walmart LabsMediumSoftware EngineerMinimize Cost for Feature-Capable Models
This problem tests your ability to use greedy strategies or dynamic programming to satisfy coverage constraints while minimizing total costs from a set of available items.
Coding & AlgorithmsOnline AssessmentGreedyOptimizationCombinatorics - Walmart LabsMediumSoftware EngineerMinimize the Maximum Edge on a Path
Find a path in a weighted undirected graph that minimizes its largest edge rather than the sum of weights. Handle parallel edges, disconnected vertices, and the start-equals-target case efficiently at large graph scale.
Coding & AlgorithmsOnline Assessment - Walmart LabsMediumData ScientistPredict Next-Period Conversion Rate Using Historical Campaign Data
This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Predict Next-Period Conversion Rate Using Historical Campaign Data states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Machine LearningOnsite - Walmart LabsHardSoftware EngineerProduct of All Other Elements for Each Index Without Division
For each position of an integer array, compute the product of all the other elements in linear time and without using division. It tests careful handling of zeros, negative values and repeated values, and planning a single efficient pass when the obvious division shortcut is not allowed.
Coding & AlgorithmsOnsite - Walmart LabsEasyMachine Learning EngineerResolve Technical Conflict and Align Across Teams
Practice explaining technical conflict, cross-team priorities, decision ownership, dissent, and the follow-through that turns agreement into working alignment.
Behavioral & LeadershipOnsite - Walmart LabsHardSoftware EngineerShortest 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 - Walmart LabsMediumData ScientistUnderstand Propensity Score Matching in Business Analytics
This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Understand Propensity Score Matching in Business Analytics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Statistics & MathOnsite - Warner Bros DiscoveryMediumSoftware EngineerDesign 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 EngineerImplement 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 EngineerImplement 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 - WayfairEasyData ScientistClean scores and return top 5 students
This problem tests your ability to clean tabular data by performing conditional imputation and applying window functions to rank performance metrics.
Data Manipulation (SQL/Python)Online AssessmentPandasData CleaningImputation - WayfairEasyData ScientistDerive insights and improve complaint resolutions
This problem tests the ability to join disparate datasets to identify trends, evaluate the effectiveness of resolution strategies, and design an A/B test to validate potential improvements in customer satisfaction.
Analytics & ExperimentationOnline AssessmentSQLCausal InferenceA/B Testing - WayfairMediumSoftware EngineerDesign the Domain Model for an Automated Parking Garage
This problem tests object-oriented design skills by requiring the modeling of physical interactions (vehicles, spots, sensors) and transactional state management in an automated parking system.
Software Engineering FundamentalsOnsiteObject-Oriented DesignConcurrencyState Machine - WayfairMediumApplied ScientistEvaluate Post-Purchase Recommendation Emails
Evaluate post-purchase recommendation emails through incremental profit, useful timing, customer eligibility, randomized holdouts, and unsubscribe or complaint guardrails.
Product / Decision MakingOnsite - WayfairEasyData ScientistFind top buyer in earliest 10-year window
This question tests the ability to filter data by date ranges, group transactional records by user, and use window functions or aggregations to identify a specific record based on criteria.
Data Manipulation (SQL/Python)Online AssessmentSQLAggregationWindow Functions - WayfairEasyData ScientistHow to improve complaint resolution
This question evaluates a candidate's competency in data-driven analytics, causal inference, metrics design, and experimentation for customer support performance.
Analytics & ExperimentationOnline Assessment - WayfairHardSoftware EngineerMaximize 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 ScientistRank Homepage Modules for an E-Commerce Product
Rank e-commerce homepage modules using business objectives, seasonal eligibility, slot effects, slate diversity, cold-start exploration, and page-level experiments.
ML System DesignOnsite
Walmart Labs
Wayfair