practice a little every day, paws crossed ♡
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 9031–9060 of 9403 results
- 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 - VoleonMediumSoftware EngineerImplement sparse matrix addition and multiplication
This question evaluates implementation skills for sparse matrix addition and multiplication, focusing on data structure selection, algorithmic complexity, memory efficiency, and explicit error handling within the Coding & Algorithms domain and the linear algebra/data-structures crossover.
Coding & AlgorithmsTechnical Screen - VoleonMediumData ScientistLoad and visualize large CSV robustly
This question evaluates competency in large-scale data manipulation and preprocessing, including robust file I/O (delimiter and encoding detection), memory-efficient chunked loading, dtype enforcement, deduplication, imputation strategy design, outlier handling, and statistical visualization techniques.
Data Manipulation (SQL/Python)Technical Screen - VoleonMediumData ScientistPre-process Financial Data for Linear Regression Modeling
This question evaluates data preprocessing and feature engineering skills—handling missing values, winsorizing outliers, standardizing predictors, and assembling X/y datasets using Python/Pandas within the Data Manipulation (SQL/Python) domain.
Data Manipulation (SQL/Python)Technical Screen - 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 - VoleonMediumQuantitative ResearcherReason About Train and Test Loss Under Regularization and More Data
Reason about train/test gaps, high losses, regularization strength, and learning curves while separating statistical tendencies from finite-sample guarantees.
Machine LearningTechnical Screen - VoleonMediumQuantitative ResearcherReturn Words in Repeated Anagram Groups
Return all input occurrences belonging to repeated anagram groups, preserving order and duplicates with multiplicity-aware letter-count signatures.
Coding & AlgorithmsTechnical Screen - VoleonMediumSoftware EngineerSimulate an exchange and participation-rate trading
This question evaluates competency in designing and implementing event-driven simulators, priority-based matching algorithms, and quota-constrained allocation for a limit order book, participation-rate execution, and multi-client fair-share distribution in the Coding & Algorithms domain.
Coding & AlgorithmsTechnical Screen - VoleonEasyData ScientistSolve Markov, OLS-rotation, and coin-toss probability
This multi-part question evaluates understanding of Markov chain and stochastic matrix properties, linear-algebra facts about eigenvalues and stationary distributions, invariance and sampling-distribution properties of OLS under orthonormal rotations, and discrete stopping-time probability reasoning for coin-flip processes.
Statistics & MathTechnical Screen - VoleonHardSoftware EngineerSolve classic coding interview problems
Determine the minimum number of trials needed to find the highest safe floor in an n-story building using at most k eggs in the worst case.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingBinary SearchCombinatorics - VoleonMediumSoftware EngineerValidate whether a binary string is good
This question evaluates understanding of recursive grammars and string parsing, focusing on designing linear-time algorithms and managing space constraints for validity checks on binary strings.
Coding & AlgorithmsTechnical Screen - Walmart LabsMediumSoftware EngineerAnswer Spring Boot and Thymeleaf engineering questions
This problem tests your understanding of Spring Boot MVC architecture, specifically how to manage session-scoped state, optimize view rendering, and implement robust server-side validation using Thymeleaf.
Software Engineering FundamentalsTechnical ScreenSpring BootThymeleafJava - Walmart LabsMediumSoftware EngineerAnswer leadership scenarios about influence and integrity
This question evaluates leadership competencies including influence without formal authority, data-driven decision-making, incident response and ethical integrity/compliance judgment in a software engineering context.
Behavioral & LeadershipTechnical Screen - 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 LabsMediumSoftware EngineerCheck whether brackets are balanced
This problem tests your ability to handle nested structures using a stack data structure to track opening symbols and verify matching closing symbols.
Coding & AlgorithmsTechnical ScreenStackString ManipulationData Structures - Walmart LabsMediumSoftware EngineerCompare Quicksort and Mergesort in Practice
This problem tests your deep understanding of sorting algorithm internals beyond asymptotic complexity, focusing on practical trade-offs in memory, stability, and data characteristics.
Software Engineering FundamentalsTechnical ScreenAlgorithmsSystem DesignSorting - Walmart LabsMediumSoftware EngineerCompute days until plants stop dying
This question evaluates a candidate's ability to reason about array-based state transitions and algorithmic complexity, testing competency in analyzing iterative dependencies among elements and handling large input sizes.
Coding & AlgorithmsTechnical Screen - Walmart LabsMediumSoftware EngineerCompute the Minimum Number of Meeting Rooms
Determine the minimum number of meeting rooms required to accommodate a set of schedule intervals where intervals are half-open and meetings can start at the exact moment another ends.
Coding & AlgorithmsTechnical Screenintervalssortingheap - Walmart LabsMediumSoftware EngineerCount ways to make change (DP)
This problem tests the ability to solve the classic 'Coin Change II' problem using dynamic programming to count the number of unique combinations that sum up to a target amount.
Coding & AlgorithmsTechnical ScreenDynamic ProgrammingCombinatoricsOptimization - Walmart LabsMediumSoftware EngineerDescribe past projects and impact
This question evaluates ownership, technical decision‑making, system design trade-offs, cross‑team leadership, execution discipline and impact measurement within software engineering projects.
Behavioral & LeadershipTechnical Screen - Walmart LabsMediumSoftware EngineerDesign Spring Boot for high availability and background work
This question tests the ability to scale a stateless Spring Boot service while ensuring reliable execution of asynchronous background tasks in a distributed environment.
System DesignTechnical ScreenSpring BootScalabilityMessaging - 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 Large-Scale Real-Time Temperature Collection System
Design an end-to-end IoT temperature telemetry platform capable of ingesting high-throughput sensor streams, handling out-of-order data, projecting real-time status, and managing long-term time-series storage.
System DesignTechnical ScreenIoTTime SeriesDistributed Systems - Walmart LabsMediumSoftware EngineerDesign a Metrics Monitoring Dashboard
This question tests the ability to architect a scalable time-series data pipeline, focusing on ingestion, storage strategies for high-throughput metric data, and query performance for dashboard visualization.
System DesignTechnical ScreenScalabilityTime SeriesObservability - 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 LabsMediumSoftware EngineerDesign a multi-carrier parcel delivery system
This question evaluates system design and integration competencies, including distributed architecture, API design, data modeling, reliability, scalability, and handling heterogeneous third-party carrier integrations for a multi-carrier parcel shipping platform.
System DesignTechnical Screen - 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
Voleon
Walmart Labs