Frontend System Design
Practice designing complex UI systems the way senior engineers do at Google, Meta, and top product companies. Use a whiteboard, get AI evaluation, and see a rubric-based coaching report on your architecture decisions.
These open-ended design questions test your ability to architect scalable, performant, and accessible UIs. Each is evaluated on component design, state management, performance, and tradeoff reasoning.
Design a search input that shows suggestions in real-time. Cover debouncing, caching previous results, keyboard navigation, accessibility, and handling slow/failed API calls.
Design a social media feed that loads more content as the user scrolls. Cover virtualization, pagination strategy, optimistic updates, and skeleton loading states.
Design a video player component. Cover playback controls, buffering state, quality selection, captions, picture-in-picture, and keyboard shortcuts.
Design a collaborative document editor. Cover real-time sync, conflict resolution (CRDT/OT), cursor presence, offline support, and permission controls.
Design a multi-step checkout form. Cover step navigation, validation per step, progress indicator, back-navigation with state preservation, and error recovery.
Design a real-time chat UI. Cover WebSocket management, message ordering, typing indicators, read receipts, optimistic message rendering, and reconnection logic.
Senior engineers use a structured approach. Practice it until it's natural.
Ask about scale, target users, key features vs nice-to-haves, and constraints. This shows senior-level thinking before jumping to solutions.
Break the UI into components. Define component boundaries, data flow direction, and which components own state.
Decide what state goes where — local, lifted, or global. Define the data model, API contracts, and caching strategy.
Cover loading states, error states, empty states, virtualization for long lists, lazy loading, and network failure recovery.
Do you break the UI into well-defined, reusable components with clear ownership and a unidirectional data flow?
Do you choose the right level for state — local, lifted, or global? Do you avoid over-engineering with unnecessary stores?
Do you proactively identify bottlenecks — large lists, heavy renders, network waterfalls — and address them with concrete strategies?
Do you define clean interfaces between components and APIs? Do you handle caching, pagination, and optimistic updates?
Do you address keyboard navigation, ARIA roles, focus management, and screen reader compatibility without being prompted?
Can you compare alternatives (CSR vs SSR, Context vs Zustand, polling vs WebSockets) and justify your choices with clear reasoning?
A frontend system design interview asks you to architect a complex UI feature or application from scratch — for example, design a YouTube video player, an autocomplete search, a news feed, or a collaborative document editor. You're evaluated on component architecture, state management strategy, API design, performance considerations, accessibility, and error handling. These interviews are common at Google, Meta, Amazon, and senior frontend roles.
Frontend system design interviews cover: component hierarchy and API design (props, composition), state management (local vs global, React Context vs external stores), data fetching and caching strategies, performance (lazy loading, virtualization, code splitting), real-time updates (WebSockets, polling, SSE), accessibility (ARIA, keyboard navigation), error handling and loading states, and cross-browser/device considerations.
Common frontend system design questions include: Design an autocomplete/typeahead, Design a news feed (Twitter/Facebook), Design a video player (YouTube), Design a collaborative document editor (Google Docs), Design an e-commerce product page, Design a real-time chat application, Design a photo gallery with infinite scroll, Design a multi-step form, and Design a drag-and-drop interface.
Backend system design focuses on servers, databases, load balancing, and distributed systems. Frontend system design focuses on client-side architecture — component structure, state management, browser APIs, rendering strategies (CSR/SSR/SSG), network request optimization, bundle size, caching in the browser, and user experience. Frontend system design tests how you think about building UIs that are performant, accessible, and maintainable at scale.
Use a live whiteboard, answer open-ended design questions, and get a rubric-based coaching report on your component architecture, state management, and tradeoff reasoning.