Interview practice

Frontend Machine Coding Practice

94 real interview rounds β€” React, hooks, DOM widgets & core JS. Build each one live; tests grade it instantly.

94problems49medium11hard0solved5free

NewAI mentor β€” progressive hints & code review, in the editor.

Prep for your target company

#Title
Image CarouselFreeβš›οΈReact Components
M
Implement DebounceFree⚑Utility Functions
M
Star Ratingβš›οΈReact Components
M
Tabs🌐DOM Manipulation
M
Search Filter🌐DOM Manipulation
M
useHistory HookπŸͺReact Hooks
H
Traffic Lightβš›οΈReact Components
E
Implement ThrottleFree⚑Utility Functions
M
Modal Dialogβš›οΈReact Components
M
Todo Listβš›οΈReact Components
M
Deep Clone ObjectFree{ }Objects
H
Tic Tac Toeβš›οΈReact Components
M
Accordion🌐DOM Manipulation
M
Flatten ArrayFree[ ]Arrays
E
Counterβš›οΈReact Components
E
Like Buttonβš›οΈReact Components
E
Toggle Switchβš›οΈReact Components
E
Paginationβš›οΈReact Components
M
Quantity Stepperβš›οΈReact Components
E
Dropdown Menu🌐DOM Manipulation
M
Tag Input🌐DOM Manipulation
M
Select All Checkboxes🌐DOM Manipulation
M
Tooltip🌐DOM Manipulation
M
Color Swatchesβš›οΈReact Components
E
Progress Stepperβš›οΈReact Components
M
useToggle HookπŸͺReact Hooks
E
useCounter HookπŸͺReact Hooks
E
usePrevious HookπŸͺReact Hooks
M
useArray HookπŸͺReact Hooks
M
useBoolean HookπŸͺReact Hooks
E
useStep HookπŸͺReact Hooks
M
useInput HookπŸͺReact Hooks
E
useClampedCounter HookπŸͺReact Hooks
M
useSelection HookπŸͺReact Hooks
M
Segmented Control🌐DOM Manipulation
E
Transfer List🌐DOM Manipulation
M
Breadcrumb Trail🌐DOM Manipulation
E
Shopping Cartβš›οΈReact Components
M
Toast Stackβš›οΈReact Components
M
Vote Widgetβš›οΈReact Components
E
Character Counter🌐DOM Manipulation
E
Implement Promise.allπŸ”„Promises & Async
M
Implement MemoizationπŸš€Performance
M
Implement Event Emitter🧩Design Patterns
M
Implement Curry FunctionΞ»Functional Programming
H
Chunk Array[ ]Arrays
E
Function CompositionΞ»Functional Programming
M
Implement Promise.raceπŸ”„Promises & Async
M
Implement PipeΞ»Functional Programming
E
Implement Once⚑Utility Functions
E
Array Intersection[ ]Arrays
E
Implement groupBy[ ]Arrays
E
LRU Cache🧩Design Patterns
H
Retry with BackoffπŸ”„Promises & Async
M
Simple Observable🧩Design Patterns
H
Implement Range⚑Utility Functions
E
Get Nested Value{ }Objects
M
Implement Promise.anyπŸ”„Promises & Async
M
Array Difference[ ]Arrays
E
Type Checker⚑Utility Functions
E
Implement Promise.allSettledπŸ”„Promises & Async
M
Pub/Sub System🧩Design Patterns
M
Rate Limiter⚑Utility Functions
H
Implement JSON.stringify{ }Objects
H
Implement Clamp⚑Utility Functions
E
Deep Equality Check⚑Utility Functions
M
camelCase to kebab-case⚑Utility Functions
E
String Template Parser⚑Utility Functions
M
Compact Array⚑Utility Functions
E
Pick Object Keys⚑Utility Functions
E
Omit Object Keys⚑Utility Functions
E
Set Nested Value⚑Utility Functions
M
Deep Merge Objects⚑Utility Functions
M
Deep Freeze Object⚑Utility Functions
E
Fisher-Yates Shuffle⚑Utility Functions
M
Unique By Key Function⚑Utility Functions
E
Promise with Timeout⚑Utility Functions
M
Safe JSON Parse⚑Utility Functions
E
Delay Queue⚑Utility Functions
M
Parallel LimitπŸ”„Promises & Async
H
Cancellable PromiseπŸ”„Promises & Async
M
Create DeferredπŸ”„Promises & Async
E
Async Map with ConcurrencyπŸ”„Promises & Async
M
Async Task QueueπŸ”„Promises & Async
H
SemaphoreπŸ”„Promises & Async
H
Retry Until PredicateπŸ”„Promises & Async
M
Batch Async ProcessingπŸ”„Promises & Async
M
Async DebounceπŸ”„Promises & Async
M
Async WaterfallπŸ”„Promises & Async
M
Promise Worker PoolπŸ”„Promises & Async
H
Race with TimeoutπŸ”„Promises & Async
E
Promise SequenceπŸ”„Promises & Async
E
Auto-Retry FetcherπŸ”„Promises & Async
M
Promise ThrottleπŸ”„Promises & Async
M
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