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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 1–30 of 51 results
- AirwallexMediumFrontend EngineerName-Keyed Async Task Scheduler with Sequential Lanes, Cancel and Clear by Name
Implement a JavaScript task scheduler for async functions where tasks sharing a name run strictly in order while tasks with different names run concurrently. Follow-ups add cancelling the running task for a name and clearing every running and queued task by name, testing promise handling, race conditions and API design.
Software Engineering FundamentalsTechnical Screen - AmazonMediumFrontend EngineerBuild Accessible Data-Loading Popovers for Multiple Buttons
This problem tests the ability to build a robust, accessible UI component that manages asynchronous data fetching, state synchronization, and DOM-level focus management.
Software Engineering FundamentalsOnsiteFrontendReactAccessibility - AmazonMediumFrontend EngineerDesign a Debounced Product Search Box
Design and implement an accessible, resilient product search-as-you-type component featuring debounced requests, race-condition handling via request cancellation, client-side caching, and keyboard navigation.
Software Engineering FundamentalsOnsitefrontendjavascriptreact - AmazonMediumFrontend EngineerImplement an Accessible Autocomplete Search Component
Design and implement an accessible, race-condition-resilient autocomplete search component in React or modern JavaScript, focusing on debounced queries, ARIA combobox semantics, and keyboard navigation.
Software Engineering FundamentalsTechnical ScreenReactAccessibilityFrontend - AmazonMediumFrontend EngineerPredict JavaScript let and var Behavior
Tests deep understanding of JavaScript variable declarations (var vs let), focusing on hoisting, the Temporal Dead Zone (TDZ), block vs function scoping, and per-iteration lexical bindings in asynchronous loops.
Software Engineering FundamentalsOnsitejavascriptclosureshoisting - AndurilMediumFrontend EngineerDiagnose a Memory Leak in a JavaScript Web Application
Tests your ability to identify common JavaScript memory leak patterns—such as detached DOM trees, uncleared event subscriptions, and unbounded closures—and verify resolution using browser heap profiling techniques.
Software Engineering FundamentalsOnsiteJavaScriptPerformanceMemory Management - AppleMediumFrontend EngineerBuild an Accessible Recursive Expand-and-Collapse Tree in React
This problem tests recursive component design in React, state management for nested data structures, and the implementation of WAI-ARIA standards for accessible UI components.
Software Engineering FundamentalsTechnical ScreenReactFrontendAccessibility - AppleMediumFrontend EngineerDiagnose Cold-Load and Massive-Table Performance in a Web App
This problem tests your understanding of critical path rendering optimization for cold loads and memory management strategies for handling massive datasets in a browser environment.
Software Engineering FundamentalsTechnical ScreenPerformanceDOMReact - AppleMediumFrontend EngineerExplain JavaScript Scope, Closures, Timers, and the Event Loop
Tests deep understanding of the JavaScript runtime, specifically lexical scope, closures, the distinction between task and microtask queues in the event loop, and browser script loading mechanics.
Software Engineering FundamentalsTechnical ScreenJavaScriptEvent LoopClosures - AtlassianHardFrontend EngineerBuild a 2x3 React Feed Grid from Static Data, Then from an API, and Explain Your Hooks
A front-end coding exercise: show feed items with an id, text and creation time in a two-row, three-column React grid, first from static data and then from a provided API. It tests CSS grid layout, data fetching with loading and error states, effect cleanup, and how clearly the candidate explains the React hooks they use.
Software Engineering FundamentalsTechnical Screen - AtlassianMediumFrontend EngineerBuild a Social Feed List in HTML/CSS, Then Render It from a Mock API
A two-stage front-end coding exercise: build a Twitter-style social feed list with HTML and CSS, then render it from a mock API. It tests semantic markup, a resilient card layout, asynchronous loading with loading and error states, and safe rendering of user-generated text.
Software Engineering FundamentalsTechnical Screen - CensysMediumFrontend EngineerAdd Case-Insensitive Search to a Support Ticket Queue UI and Debug Its Behavior
A frontend exercise on an existing support ticket queue with Unresolved and Archived tabs, a ticket list and an activity panel: make the search box filter tickets by title or assignee regardless of letter case, then debug parts of the app that misbehave. It tests reading unfamiliar code, state design and systematic debugging.
Software Engineering FundamentalsTechnical Screen - CitadelEasyFrontend EngineerBuild a Real-Time Event Feed Dashboard
Implement a robust React hook to manage a high-frequency, real-time event feed dashboard with pause/resume controls, out-of-order de-duplication, memory bounding, and rolling time-window statistics.
Software Engineering FundamentalsTechnical Screenreacttypescriptsliding-window - CohereMediumFrontend EngineerBuild a Credit Card Form With Validation and Linked Input Fields
A front-end UI coding question: build a credit card form with card number, name, expiry and security code, where every field is validated and the fields are linked, so the detected card network changes formatting and security-code rules. It tests state design, caret-safe input formatting, error timing, accessibility and safe handling of card data.
Software Engineering FundamentalsOnsite - CoinbaseHardFrontend EngineerImplement a Reusable Dropdown Component
This question evaluates skills in reusable frontend component design, including API design, state management (controlled vs uncontrolled), event handling, keyboard navigation, and accessibility (roles, focus behavior, and ARIA) for production-ready UI components.
Software Engineering FundamentalsOnsite - 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 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 - 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 - 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 - 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 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 - 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 - 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 - 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
Airwallex
Amazon
Apple
Atlassian
Citadel
Cohere
Coinbase
Databricks
Glean
Harvey
HubSpot
Jane Street
Okta
Ramp
Robinhood
Roblox
Snowflake