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Frontend Engineer 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 31–60 of 93 results
- DatabricksMediumFrontend EngineerDesign a Collaborative Playlist Editor
Tests your ability to architect a real-time collaborative frontend application, focusing on client-side state synchronization, deterministic list ordering, idempotent mutation protocols, and graceful network reconnection.
System DesignOnsiteFrontendReal-TimeData Modeling - DatabricksMediumFrontend EngineerImplement Resilient Autocomplete Data Fetching
Implement resilient autocomplete fetching with a quiet period, bounded retries, newest-query precedence, and reuse of recent results. Cover empty input, out-of-order responses, cancellation during waits and requests, error classification, freshness and capacity policies, unmount safety, accessibility, shared requests, and responsive ranking.
Software Engineering FundamentalsOnsite - EquinixMediumFrontend EngineerPlan Testing and Deployment for a React Feature
This question assesses a candidate's ability to architect a robust, production-ready React feature by integrating state persistence, error handling, testing strategies, and safe deployment practices.
Software Engineering FundamentalsHR ScreenReactFrontend ArchitectureTesting Strategy - GleanMediumFrontend EngineerBuild a React Social Feed with Upvote/Downvote Re-Sorting and Pinned Posts
Build a React social feed where upvotes and downvotes re-sort posts by score in descending order and pinned posts stay at the top. Tests state design and immutable updates, correct vote-toggle arithmetic, deterministic ordering, accessibility and optimistic persistence with rollback.
Software Engineering FundamentalsOnsite - GleanMediumFrontend EngineerDesign Real-Time Typeahead for Enterprise Search: History, People, Docs, Apps, Filters
Design real-time typeahead for an enterprise search product that suggests past searches, people, documents, apps and filters as the user types. Tests client request policy and stale-response handling, accessible combobox UI, permission-aware backend fan-out, blending across sources and latency budgets.
System DesignOnsite - GleanMediumFrontend EngineerImplement Two-Player Connect Four on a 6x7 Board with Win and Draw Detection
Implement two-player Connect Four on a 6x7 board: drop discs into columns, detect four in a row in every direction, handle full columns and draws, and render a playable interface. Tests clean separation of game logic from UI, efficient win checks from the last move and careful edge handling.
Software Engineering FundamentalsOnsite - GoogleHardFrontend EngineerCount Islands with Diagonal Connectivity
Practice counting binary-grid components when diagonal neighbors connect, changing the usual four-direction island definition.
Coding & AlgorithmsOnsite - GoogleHardFrontend EngineerDesign an Embeddable Streaming Chat Interface
Design an embeddable chat-agent widget with resumable streaming, virtualized history, safe caching, accessibility, and meaningful metrics.
System DesignOnsite - GoogleHardFrontend EngineerExplain Motivation for an Experimental Technology Team
Craft a credible motivation answer for an experimental technology team by connecting mission interest with evidence-driven, responsible execution.
Behavioral & LeadershipOnsite - GoogleHardFrontend EngineerVisualize More Than One Hundred Million Map Points
Design a multiresolution map that turns over one hundred million points into cached heat maps and detailed pins without overwhelming the browser.
System DesignOnsite - HarveyMediumFrontend EngineerBuild a Virtualized React Spreadsheet with Cell Formulas
Design and implement a virtualized React spreadsheet component supporting editable cells, formula evaluation with string concatenation, cycle detection, and targeted re-rendering.
Software Engineering FundamentalsTechnical ScreenReactVirtualizationGraph Algorithms - HarveyMediumFrontend EngineerDesign a Chat Application with Durable Conversation History
Design persistent real-time chat with conversation ordering, idempotent sends, paginated history, optimistic state, delivery receipts, and reconnect catch-up.
System DesignOther - HubSpotMediumFrontend EngineerJavaScript Fundamentals: Prototype Chains and How 'this' Is Bound
A JavaScript fundamentals question that asks you to predict and explain how this is bound in method calls, detached calls, bound functions and arrow functions, trace property lookup through a prototype chain, and rewrite constructor-based inheritance with class syntax. It tests precise reasoning about core language behaviour.
Software Engineering FundamentalsOnsite - Jane StreetMediumFrontend EngineerBuild a Web Calculator That Matches a Reference App
This question evaluates frontend engineering competencies—interactive UI implementation, state management, event-driven logic, and visual layout fidelity—within the domain of software engineering fundamentals and web frontend development.
Software Engineering FundamentalsTechnical Screen - Jane StreetMediumFrontend EngineerField Layout: getOffset and insert
This question evaluates a candidate's ability to model and maintain ordered field layouts by computing and updating byte offsets, testing competencies in dynamic sequence data structures, cumulative offset tracking, and efficient update/query operations.
Coding & AlgorithmsTechnical Screen - MomentMediumFrontend EngineerBuild a Race-Free Memory Card Game in React
Work through the state and timing logic for a React memory-card game that remains correct under rapid clicks and restarts. The exercise examines stale closures, input locking, timeout cleanup, stable card identity, accessible interaction, and tests for race-prone transitions.
Software Engineering FundamentalsTechnical Screen - OktaMediumFrontend EngineerDeduplicate an Array in Linear Time
This question tests the ability to implement a deduplication algorithm that preserves the original relative order of elements while maintaining O(n) time and space complexity.
Coding & AlgorithmsTechnical ScreenArraysHash TableTime Complexity - OktaMediumFrontend EngineerDesign High-Throughput Messaging Infrastructure
This problem tests your ability to design a scalable, reliable messaging system by balancing throughput, latency, and data persistence in a high-concurrency environment.
System DesignTechnical ScreenScalabilityMessagingConcurrency - OktaMediumFrontend EngineerReview Code for Memory Risks
This question tests your ability to identify memory-intensive patterns and performance bottlenecks in JavaScript array manipulation, specifically regarding garbage collection and object reference stability.
Software Engineering FundamentalsTechnical ScreenJavaScriptComplexity AnalysisMemory Management - OpenAIMediumFrontend EngineerBuild a Streaming Chat Input
This question evaluates frontend engineering skills including streaming data handling, incremental token-by-token rendering, asynchronous state management, and preserving UI responsiveness during long-running API streams.
Coding & AlgorithmsTechnical Screen - RampMediumFrontend EngineerBuild a React Word-Guessing Game with Green, Yellow, and Red Letter Feedback
A front-end exercise to build a small React word-guessing game in JavaScript or TypeScript, where each submitted guess appears as a row of letter cells colored green, yellow, or red against a target word. It tests component state design, input validation, and a clearly specified letter-scoring rule, including repeated letters.
Software Engineering FundamentalsOnline Assessment - RampEasyFrontend EngineerBuild a Wordle Guess Checker with Green, Yellow and Red Letter Feedback
Build a small Wordle-style component that accepts a guess of up to five letters and colors each letter green, yellow or red against a fixed secret word, tested with SPEND. Tests input handling, pure scoring logic, repeated-letter rules and simple UI state under a 45-minute limit.
Software Engineering FundamentalsOnline Assessment - RampMediumFrontend EngineerBuild a Wordle-Style Game in React
Implement a 5-letter, 5-guess Wordle-style game in React featuring correct duplicate-letter evaluation, virtual and physical keyboard support, and proper game-state transitions.
Software Engineering FundamentalsOnline Assessmentreactfrontendstate-management - RobinhoodMediumFrontend EngineerBuild a Chainable Rectangle Manipulation API
This problem tests your ability to design a fluent interface (method chaining) that manages an internal queue of asynchronous operations to ensure tasks execute sequentially.
Software Engineering FundamentalsTechnical ScreenJavaScriptFluent-APIAsync - RobinhoodMediumFrontend EngineerBuild a Weekly Calendar
This question evaluates frontend UI engineering skills, focusing on interactive interface construction, event handling, and state modeling to maintain a single source of truth for events in a weekly calendar grid, and it belongs to the web frontend development and UI/state-management domain.
Coding & AlgorithmsOnsite - RobinhoodMediumFrontend EngineerDesign a Photo Album App
This question evaluates proficiency in frontend system design, specifically client-side component and data architecture, state management and normalization, real-time synchronization, and large-media upload flows; it sits in the System Design domain with a Frontend Engineer focus and tests practical application of these competencies.
System DesignOnsite - RobloxHardFrontend EngineerBuild a Configurable Two-Player Tic-Tac-Toe Board in React
Tests your ability to architect a scalable, accessible React component with dynamic state, efficient win-detection logic for large grid sizes, and robust handling of prop updates.
Software Engineering FundamentalsTechnical ScreenReactFrontendState Management - RobloxMediumFrontend EngineerDesign a Reusable Dropdown Menu Component
Tests a candidate's ability to architect a production-grade, reusable UI component library element with consideration for flexible API design, accessibility (WAI-ARIA), state management, and large dataset performance.
System DesignOnsiteFrontend System DesignReactAccessibility - RobloxMediumFrontend EngineerExecutive-Round Behavioral: Proactive Decision-Making in Career and Projects
This question assesses the candidate's ability to demonstrate agency, self-reflection, and proactive decision-making when navigating complex professional transitions and high-stakes technical trade-offs.
Behavioral & LeadershipOnsiteBehavioralLeadershipDecision-Making - SnowflakeMediumFrontend EngineerBuild an Arrow-Controlled Kanban Board in React
Design and implement a performant React Kanban board in TypeScript with normalized state and accessible arrow controls for shifting tasks across ordered columns at scale.
Software Engineering FundamentalsTechnical Screenreacttypescriptfrontend
Databricks
Glean
Google
Harvey
HubSpot
Jane Street
Okta
OpenAI
Ramp
Robinhood
Roblox
Snowflake