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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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- 546
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Showing 3481–3510 of 3640 results
- VersemedicalMediumSoftware EngineerBuild a Paginated Provider Search Backend and React Filter UI
This problem tests full-stack proficiency, focusing on efficient database querying with optional filters, secure backend API design, and responsive frontend state management.
Software Engineering FundamentalsOnsiteSQLReactREST API - VersemedicalMediumSoftware EngineerFind Strictly Decreasing Forecast Windows for Equatorial Cities
This problem tests the ability to handle API integration, data stream processing, and sliding window logic while managing error handling and rate-limiting constraints.
Software Engineering FundamentalsOnsiteAPIsData ProcessingPostgreSQL - Virtu FinancialHardQuantitative ResearcherApproximate a Binomial Upper Tail with a Normal Distribution
This question tests the application of the Normal approximation to the Binomial distribution, the use of continuity correction, and the ability to evaluate the error bounds of this approximation.
Statistics & MathOnsiteStatisticsProbabilityNormal Approximation - Virtu FinancialHardQuantitative ResearcherApproximate a Rare-Event Binomial Probability
This problem tests the application of the Poisson approximation to binomial distributions for rare events and the evaluation of the error bounds associated with this approximation.
Statistics & MathOnsiteProbabilityPoisson DistributionBinomial Distribution - Virtu FinancialHardQuantitative ResearcherBirthday Collisions and the Closest Pair of Birthdays
This problem tests your understanding of probability theory, specifically the generalized birthday paradox, and your ability to analyze spacing distributions of random variables.
Statistics & MathOnsiteProbabilityStatisticsCombinatorics - Virtu FinancialHardQuantitative ResearcherCompare Two Strategies for Getting Ten Consecutive Heads
This problem tests your ability to model probability through recursion and expectation, specifically comparing the efficiency of two distinct strategies for achieving a target streak of coin tosses.
Statistics & MathOnsiteProbabilityExpectationRecurrence - Virtu FinancialHardQuantitative ResearcherMaximum Edges in a Triangle-Free Graph
Determine the maximum number of edges an undirected, simple graph on n vertices can have without containing any triangle (K3), and construct one such extremal graph.
Coding & AlgorithmsOnsitegraph-theorymathcombinatorics - VisaMediumSoftware EngineerAssemble a RAG Pipeline From Provided Python Interfaces and Explain Retrieval
Assemble a retrieval-augmented generation pipeline from provided Python interfaces, covering chunking, embedding, vector search and grounded prompting, then explain why embeddings and cosine similarity work for retrieval and when RAG beats fine-tuning or long context. It tests applied LLM engineering and clear reasoning with unfamiliar tooling.
Machine LearningOnsite - VisaMediumSoftware EngineerDesign a Ride-Hailing Backend That Matches Riders With Nearby Drivers
Design the backend of an Uber-style ride-hailing service that matches riders with nearby drivers, streams live locations, and tracks trips to completion. It tests requirement scoping, geospatial indexing for moving drivers, race-free dispatch, real-time updates, failure handling, and the ability to lead a design discussion.
System DesignOnsite - VisaMediumSoftware EngineerDesign rotating warehouse simulator with closures
This question evaluates algorithmic skills in designing efficient dynamic data structures and performing event-driven simulation with mutable state, specifically managing cyclic capacity resets and permanent closures in the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - VisaMediumSoftware EngineerFind the Index of a Target in a Sorted Array of Distinct Integers
Practice locating a target value in a strictly increasing array of distinct integers, returning its zero-based index or -1 when it is absent. The task checks logarithmic-time search over sorted data, precise loop boundaries, and correct handling of single-element arrays and values that fall between or outside the stored elements.
Coding & AlgorithmsOnsite - VisaMediumSoftware EngineerJava Fundamentals: Polymorphism and Monolith Versus Microservices
A Java fundamentals question pair: explain polymorphism, including overriding, dynamic dispatch and overload resolution, and compare monolithic and microservices architectures. It tests precise language mechanics, concrete examples, and balanced reasoning about deployment, scaling, consistency and operational trade-offs.
Software Engineering FundamentalsOnsite - VisaMediumSoftware EngineerLongest Strictly Rising Four-Direction Walk in an Integer Grid
A grid coding problem: find the length of the longest walk of strictly increasing values in an integer matrix, moving only up, down, left or right. It tests modeling a grid as a graph, handling equal neighboring values correctly, and an efficient search over grids of up to 40,000 cells.
Coding & AlgorithmsOnsite - VisaMediumSoftware EngineerMaintain pair-sum counts under replacements
This question evaluates the ability to design dynamic data structures and perform algorithmic complexity analysis for maintaining pair-sum counts under element replacements, testing skills in efficient query/update handling and scalability.
Coding & AlgorithmsOnsite - VoleonHardSoftware EngineerImplement Kac ring with O(1) color and kstep
This question evaluates understanding of algorithmic state representation, modular arithmetic, and efficient update/query design by requiring a Kac ring implementation that supports constant-time k-step advancement and O(1) aggregate color reporting.
Coding & AlgorithmsOnsite - VoleonHardSoftware EngineerProcess exchange prints, volume checks, and client orders
This problem tests your ability to manage high-frequency time-series data using sliding windows and stateful order tracking to enforce trading constraints.
Coding & AlgorithmsOnsiteSliding WindowStream ProcessingTime-Series - Walmart LabsMediumData ScientistAssess Cultural Fit in Informal Hiring Conversations
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Assess Cultural Fit in Informal Hiring Conversations states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - Walmart LabsEasyMachine Learning EngineerDesign a Conversational Agent for Finding Vacation Rentals
Design a multi-turn assistant that turns a traveler's free-form trip description into structured, grounded rental search results. Tests where to use an LLM versus deterministic search, clarification strategy, safety against hallucination and injection, and evaluation against classic search.
ML System DesignOnsitellm-agentssearchretrieval - Walmart LabsMediumSoftware EngineerDesign a Read- and Write-Heavy Product Catalog Service
Design a scalable, highly available product catalog platform supporting both high-frequency merchant updates and massive shopper read traffic while maintaining data integrity and search consistency.
System DesignOnsitesystem-designcqrscaching - Walmart LabsEasySoftware EngineerDesign aggregator for multiple downstream services
This question assesses the ability to design an API Gateway or Aggregator service that coordinates requests to multiple downstream microservices while managing latency, partial failures, and data aggregation.
System DesignOnsiteMicroservicesConcurrencyFault Tolerance - Walmart LabsEasyMachine Learning EngineerDesign an Agentic Search Experience
Design an agentic search experience with clarifying dialogue, structured constraints, grounded retrieval, bounded tool use, and evaluation against conventional search.
ML System DesignOnsite - Walmart LabsHardSoftware EngineerDesign an E-Commerce Checkout Flow That Prevents Concurrency Bugs
Design the checkout flow for a large online retailer, from cart to a confirmed, paid order, with the emphasis on preventing concurrency bugs. It tests stock reservation without overselling, idempotent order placement and payment, handling of carts and prices that change mid-checkout, and recovery from partial failures.
System DesignOnsite - Walmart LabsEasyMachine Learning EngineerDesign an LLM agent with RAG and tools
This problem tests the ability to architect an LLM-based agent capable of retrieving information and performing actions, focusing on orchestration, tool execution, and system reliability.
Machine LearningOnsiteLLMRAGAgentic-Workflow - 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 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 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
Virtu Financial
Visa
Voleon
Walmart Labs