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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 811–840 of 3640 results
- Capital OneEasyData ScientistVisualize Price Impact on Demand and Profit Trends
Evaluates price sensitivity and profit-curve reasoning for a network service with downward-sloping demand. Strong answers explain demand curves, profit shape, marginal revenue, marginal cost, and optimal price.
Analytics & ExperimentationOnsite - Capital OneMediumData ScientistWrite SQL for theme-park revenue and visits
This question evaluates SQL data-manipulation and analytical skills, including joins, aggregations, date-range filtering, handling multiple ticket ownership, and edge cases like zero counts when computing revenue and visit metrics.
Data Manipulation (SQL/Python)Onsite - Capital OneMediumData ScientistWrite SQL to compute campaign net revenue
This question evaluates SQL-based data manipulation and analytics skills, including aggregation, deduplication, date-range filtering, revenue and cost calculations, and selection logic for prioritizing additional donors.
Data Manipulation (SQL/Python)Onsite - CarvanaEasySoftware EngineerAnswer Cross-Functional Workplace Prompts
This question evaluates communication, conflict-resolution, cross-functional collaboration, and the candidate's ability to explain technical concepts to non-technical stakeholders, along with practical familiarity with using AI tools in engineering workflows.
Behavioral & LeadershipOnsite - CarvanaEasySoftware EngineerDesign an Attendance Payroll Service
This question evaluates system design and backend engineering skills, including API design, data modeling for time-series attendance, payroll computation logic, consistency guarantees, integration/synchronization with external sources, and strategies for handling high-volume, bursty traffic.
System DesignOnsite - CarvanaEasySoftware EngineerSpell Out a Nonnegative Integer
This question evaluates a candidate's ability to decompose integers and implement precise string-formatting logic, including mapping numeric values to their English word equivalents and managing scale units and boundary conditions.
Coding & AlgorithmsOnsite - Charta HealthMediumSoftware EngineerDesign a Prefix-Suggestion Search Interface
Design and implement an in-memory prefix suggestion engine that indexes document titles, provides ranked auto-complete results, and prevents out-of-order race conditions from asynchronous search queries.
Software Engineering FundamentalsOnsiteTrieSearchConcurrency - Charta HealthMediumSoftware EngineerExplain Your Project and Motivation for Charta Health
Explain a project through architecture, ownership, and failure handling, then connect your interests to Charta Health's verified work and the role.
Behavioral & LeadershipOnsite - Charta HealthMediumSoftware EngineerGenerate Consistent Outputs for Similar Inputs
Design a semantic caching and computation deduplication system that identifies similar inputs, prevents duplicate expensive processing under concurrent load, and maintains consistent, versioned outputs.
System DesignOnsiteDistributed SystemsCachingVector Search - Chicago Trading CompanyMediumSoftware EngineerDesign a Pre-Trade Risk Check for an Electronic Order Path
This question tests the ability to design a high-throughput, low-latency risk engine capable of atomic exposure validation before orders reach an exchange, while balancing concurrency and strict fault tolerance.
System DesignOnsiteLow LatencyConcurrencyRisk Management - Chicago Trading CompanyMediumSoftware EngineerShow Teamwork and Drive Through Difficult Engineering Situations
This question assesses a candidate's ability to balance collaborative support with personal accountability, and their resilience in overcoming high-stakes technical or organizational blockers.
Behavioral & LeadershipOnsiteLeadershipCollaborationProject Management - Chicago Trading CompanyMediumSoftware EngineerTrace Virtual Address Translation Through TLBs, Page Tables, and Caches
This question tests the understanding of memory hierarchy and virtual memory translation, specifically the interactions between TLBs, page tables, and hardware caches.
Software Engineering FundamentalsOnsiteVirtual MemoryPagingMMU - ChimeHardSoftware EngineerDesign mobile check deposit system
This question evaluates a candidate's ability to design end-to-end, production-grade mobile check deposit systems, assessing competencies in system architecture, distributed systems, security and fraud prevention, regulatory compliance (Reg CC, Check 21), data durability, and operational observability.
System DesignOnsite - ChimeMediumSoftware EngineerSimulate toppling board game outcome
This question evaluates a candidate's ability to implement a discrete board-game simulation, including state management, turn-based ownership semantics, stack-based piece handling, capture mechanics, and game termination detection.
Coding & AlgorithmsOnsite - CiscoEasySoftware EngineerDescribe How You Drove an Improvement to a Team's QA Workflow
A behavioral question for a software QA role asking how the candidate drives improvements to a team's testing and release workflow. It looks for a concrete, evidence-based example that shows root-cause diagnosis, a piloted change, stakeholder buy-in, and measured results.
Behavioral & LeadershipOnsite - CiscoEasySoftware EngineerDoes a Successful Ping Mean Port 443 Is Reachable? Diagnosing Server Connectivity
A networking fundamentals question asking whether a successful ping to a server proves that port 443 on it is accessible, and how to check the port directly. It tests the difference between ICMP and TCP, the role of firewalls and listening services, and practical connectivity troubleshooting with command-line tools.
Software Engineering FundamentalsOnsite - CiscoEasySoftware EngineerExplain BGP: Sessions, Route Exchange, and Best-Path Selection
A networking fundamentals question asking the candidate to explain the Border Gateway Protocol: why it exists, how peers form sessions and exchange routes, how a router selects the best path, and how BGP differs from interior protocols such as OSPF. It also probes troubleshooting and testing.
Software Engineering FundamentalsOnsite - CiscoEasySoftware EngineerImplement a Python To-Do Task Manager Class with CRUD and Status Rules
A Python coding question asking for a to-do task manager class with create, read, update, and delete operations, where every task has a status of new, pending, or resolved. It tests data modeling, input validation, status transition rules, error handling for missing tasks, and testable class design.
Software Engineering FundamentalsOnsite - CiscoEasySoftware EngineerPython Multiple Inheritance: Which Parent Method Runs When Names Collide
A Python fundamentals question about multiple inheritance in which two parent classes define a method with the same name and a child class inherits from both. It tests the method resolution order, C3 linearization, how super() follows that order, and when composition is the better design.
Software Engineering FundamentalsOnsite - CiscoEasySoftware EngineerPython and pytest Fundamentals: Fixtures, Decorators, and Generators
A three-part Python and pytest fundamentals question covering how fixtures are injected, scoped, torn down, and shared; how decorators work and how to write one that preserves metadata; and how generators produce values lazily. It tests core language mechanics used in test automation.
Software Engineering FundamentalsOnsite - CiscoEasySoftware EngineerTesting a New Feature: Planning Test Cases and Handling Flaky Tests
A two-part QA question on how to test a new feature and plan its test cases, and how to find, diagnose, and prevent flaky automated tests. It evaluates requirement analysis, test design techniques, risk-based prioritization, test levels, release exit criteria, and keeping a test suite trustworthy.
Software Engineering FundamentalsOnsite - CitadelMediumSoftware EngineerCompute Every Fixed-Size Submatrix Sum
Compute every contiguous fixed-size submatrix sum without mutating the input, using a padded two-dimensional prefix grid to answer each window in constant time.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerDescribe a Difficult Challenge and How You Resolved It
Practice answering a difficult-project behavioral question with one specific, decision-rich story that separates personal actions from team contributions. The sample response shows how to diagnose retry amplification in a latency incident, negotiate a safe degradation, measure the canary result, acknowledge residual risk, and explain what changed afterward.
Behavioral & LeadershipOnsite - CitadelMediumSoftware EngineerDesign a Course Registration System
Design a course registration system with relational models and APIs for enrollment, dropping, schedules, waitlists, and course browsing. The solution explains transactional capacity protection, idempotent retries, re-enrollment without duplicate rows, FIFO promotion, outbox notifications, and tests for final-seat races.
System DesignOnsite - CitadelMediumSoftware EngineerDesign a Low-Latency Metrics and Alerting Platform
Design a high-throughput, multi-tenant metrics ingestion and alerting engine capable of triggering critical alerts within two seconds. The question evaluates your knowledge of streaming architectures, time-series storage, cardinality management, and fault-tolerant notification delivery.
System DesignOnsiteTime SeriesDistributed SystemsStreaming - CitadelHardSoftware EngineerDesign a low-latency trading platform
This question tests the ability to architect a high-throughput, sub-millisecond trading system while balancing strict deterministic latency requirements with necessary safety checks.
System DesignOnsiteHFTLow-LatencyConcurrency - CitadelMediumSoftware EngineerDesign alerting for application-to-exchange mappings
This question evaluates understanding of real-time stream processing, alerting policy design, and distributed state coordination for application-to-exchange mappings, testing competencies in scalability, correctness under partitioning and duplication, and efficient aggregation of high-volume event streams.
System DesignOnsite - CitadelMediumSoftware EngineerDesign an Authenticated Online Shopping Service
Design an authenticated online shopping service with secure signup and login, user-owned carts, product browsing, and retry-safe order creation. The solution covers password hashing, session rotation, CSRF defenses, resource-level authorization, idempotency keys, immutable order snapshots, recovery tokens, and horizontal-access tests.
System DesignOnsite - CitadelMediumSoftware EngineerDesign dynamic weighted random sampling with updates
This question evaluates a candidate's ability to design and analyze dynamic data structures that support weighted random sampling with inserts and deletes, testing skills in algorithm design, complexity analysis, and randomized sampling under large numeric constraints.
Coding & AlgorithmsOnsite - CitadelMediumSoftware EngineerGenerate Prefix-Based Product Suggestions
Generate up to three lexicographically smallest product suggestions for every prefix of a search word, with efficient handling once a prefix has no matches.
Coding & AlgorithmsOnsite
Capital One
Chime
Citadel