Design a full-featured calendar with day/week/month views, event creation, drag-to-resize, recurring events, and conflict detection.
Build a performant, swipe-friendly carousel with auto-play, infinite looping, touch/keyboard navigation, and animated transitions.
Design a real-time collaborative whiteboard using canvas, WebSockets/WebRTC, CRDT syncing, undo/redo, and multi-user presence.
Create a global modal manager with stacking, portal rendering, focus trapping, ESC handling, and dynamic modal types.
Build a multi-tab (wizard-like) form that persists data across tabs, auto-saves to localStorage or backend, handles validation per tab, and recovers on reload.
Design a performant multi-select with search, keyboard navigation, tag rendering, virtualization for large option sets, and async loading.
Design a real-time poll system using WebSockets or SSE, optimistic voting, conflict handling, caching, and animations for live result updates.
Build a scalable real-time chat UI using WebSockets, presence indicators, message queues, retries, and optimistic rendering.
Design a minimal Medium-style rich text editor with contentEditable, commands, history, block/inline formats, selection APIs, and plugins.
Design a shopping cart that updates the UI instantly (optimistic), persists to backend, and rolls back on failure. Covers conflict handling and idempotency.
Build a flexible star rating component supporting half-stars, hover preview, keyboard accessibility, and controlled/uncontrolled usage.
Design a high-performance virtualized list capable of rendering 100k+ rows with minimal DOM nodes, supporting variable heights, infinite scroll, and windowing strategies.
Design a performant, accessible data table with client-side sorting, column filtering, search, pagination, and memoization.
Design a Kanban board with drag-and-drop between columns, persistence, optimistic UI updates, and accessibility considerations.
Learn to build a dynamic form builder in React that renders form fields based on JSON schema, supports validation, conditional logic, and reusable components.
Build a resilient file upload component with progress, cancel, retry, chunking notes, and UX considerations for large files.
Build a reusable multi-step wizard in React with controlled state, validation per step, progress indicators, and persistence.
Build a global toast/notification system with portal rendering, queueing, auto-dismiss, animations, and accessibility.
Implement a fully working autocomplete component with debouncing, keyboard navigation, async suggestions, loading states, and accessibility.
Design and implement a production-ready infinite scroll in React — covers IntersectionObserver, performance, virtualization, and UX tradeoffs.