State Management Based

These test React fundamentals + thinking.

  1. ✅ Undo / Redo
  2. ✅ Debounce
  3. ✅ Throttle
  4. ✅ Form with validation
  5. ✅ Multi-step form
  6. ✅ Infinite scroll
  7. ✅ Pagination
  8. ✅ Search with caching
  9. ✅ Todo app (with edit + filter)
  10. ✅ Shopping cart logic
  11. ✅ Drag & Drop list reorder

JS Core Machine Problems

These test closures, event loop, functional JS.

  1. ✅ Implement debounce
  2. ✅ Implement throttle
  3. ✅ Promise.all polyfill
  4. ✅ Promise.any polyfill
  5. ✅ Implement bind()
  6. ✅ Implement call() / apply()
  7. ✅ Currying
  8. ✅ Deep clone object
  9. ✅ Flatten array
  10. ✅ Group by key
  11. ✅ LRU Cache (using Map)
  12. ✅ Event Emitter

UI Heavy (Very Important for FAANG)

These test real frontend skills.

  1. ✅ Autocomplete dropdown
  2. ✅ Typeahead search
  3. ✅ Modal system
  4. ✅ Toast notification system
  5. ✅ Tabs component
  6. ✅ Accordion
  7. ✅ Image carousel
  8. ✅ File uploader with preview
  9. ✅ Progress bar
  10. ✅ Star rating component
  11. ✅ OTP input component
  12. ✅ Kanban board (basic)

Performance Based

  1. ✅ Virtualized list
  2. ✅ Memoization hook
  3. ✅ Optimize re-renders
  4. ✅ Implement useDebounce hook
  5. ✅ Implement usePrevious hook

Data Structure + JS Mix (Very Common)

  1. ✅ Two Sum
  2. ✅ Valid Parentheses
  3. ✅ Sliding Window problems
  4. ✅ Frequency counter using Map
  5. ✅ Set based duplicate detection
  6. ✅ Anagram check
  7. ✅ Longest substring without repeating characters
  8. ✅ Merge intervals

Real Interview Favourite

These are VERY commonly asked:

  1. 🔥 Build Google search suggestion
  2. 🔥 Build comment tree (nested comments)
  3. 🔥 Build file explorer
  4. 🔥 Build chat UI
  5. 🔥 Build infinite feed (like LinkedIn)
  6. 🔥 Implement rate limiter
  7. 🔥 Implement retry with exponential backoff

If You Want Structured Path (Follow This Order)

  1. Debounce / Throttle
  2. Undo / Redo
  3. Autocomplete
  4. Infinite Scroll
  5. Nested Comments
  6. LRU Cache
  7. Promise polyfills
  8. Virtualization

Reality Check

For SDE1 product based:

You must be strong in:

  1. Closures
  2. Event loop
  3. Async/await
  4. Debounce/Throttle
  5. Basic DSA with Map/Set
  6. React state handling
  7. Clean component design