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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 53 results
- 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 EngineerDrive an Improvement Beyond Your Formal Responsibilities
This question assesses a candidate's ability to proactively identify technical or operational inefficiencies, influence stakeholders without formal authority, and implement measurable, sustainable improvements.
Behavioral & LeadershipOnsiteLeadershipInitiativeCollaboration - AmazonMediumFrontend EngineerFormat a Forest of Nested Comments
This problem tests your ability to reconstruct hierarchical relationships from flat input data and format them into a visual tree representation with specific character-based connectors.
Coding & AlgorithmsOnsiteRecursionTree TraversalString Formatting - AmazonMediumFrontend EngineerIntervene When Your Team Is Heading in the Wrong Direction
This question assesses a candidate's ability to identify technical or strategic misalignments within a project and their skill in providing constructive, data-driven feedback while maintaining team cohesion.
Behavioral & LeadershipOnsiteLeadershipCommunicationConflict Resolution - AmazonMediumFrontend EngineerInvestigate a Difficult Problem Until You Found the Root Cause
This question assesses the candidate's ability to systematically troubleshoot complex technical issues, demonstrate technical ownership, and implement long-term solutions rather than quick fixes.
Behavioral & LeadershipOnsiteBehavioralOwnershipDebugging - AmazonMediumFrontend EngineerLearn and Apply a Front-End Technology Across Devices
This question assesses a candidate's ability to self-teach new technologies and integrate them into a production environment while accounting for cross-platform performance and accessibility constraints.
Behavioral & LeadershipOnsiteBehavioralFrontendSelf-Learning - AmazonMediumFrontend EngineerOwn a Mistake with Real Consequences
This question assesses the candidate's integrity, ownership, and ability to implement systemic improvements following a significant professional error.
Behavioral & LeadershipOnsiteBehavioralOwnershipLeadership - 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 - 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 - CohereMediumFrontend EngineerDesign a Real-Time Comment System Front End With Optimistic Updates
Front-end system design for a real-time comment feed, centered on optimistic updates: a new comment is appended to the list before the backend confirms it, so the user can keep typing. It tests client state modeling, reconciliation with live echoes, failure and retry handling, ordering, reconnection and rendering performance.
System DesignOnsite - CoinbaseHardFrontend EngineerDesign Frontend Architecture for Trading UI
This question evaluates competency in frontend architecture for real-time trading UIs, covering state management, rendering strategies, real-time data flow, performance, reliability, security, testing, and observability.
System DesignOnsite - 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 - CoinbaseHardFrontend EngineerPresent a Previous Project Deep Dive
This question evaluates technical depth, architectural reasoning, leadership, and cross-team collaboration skills within frontend engineering, focusing on system/frontend architecture, tradeoff analysis, incident management, and measurable impact.
Behavioral & LeadershipOnsite - 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 - 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 - 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 - 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 - 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 - StripeMediumFrontend EngineerBuild and Optimize a React Interface Against an Undocumented API
Tests your ability to inspect an opaque or changing backend endpoint, build a resilient React component with typed normalization and client-side caching, and handle edge cases gracefully.
Software Engineering FundamentalsOnsitereacttypescriptcaching
Amazon
Cohere
Coinbase
Databricks
Glean
Google
HubSpot
Robinhood
Roblox
Stripe