Frontend Intermediate
Master the fundamental building blocks of modern web applications: rate limiting, DOM manipulation, asynchronous events, and state utilities tested in mid-level frontend interviews.
Curriculum Phases(4 phases · 16 problems)
Rate Limiting & Timing Controls
Handling high-frequency user actions, scroll/resize events, and polling without burning the event loop or dropping frames.
- Implement DebounceJavaScript UtilitiesEasySolve
- Implement ThrottleJavaScript UtilitiesMediumSolve
- Debounce with Leading / Immediate OptionEvent Loop & TimersMediumSolve
- Polling Function with Termination CheckEvent Loop & TimersMediumSolve
Data Normalization & UI Arrays
Transforming nested API responses, combining style classes, and manipulating client-side state without external libraries.
- Implement classNames UtilityWeb APIs & UtilitiesEasySolve
- Compact Array (Remove Falsy)Arrays & IterablesEasySolve
- Chunk Array into GroupsArrays & IterablesEasySolve
- Flatten Array (Deep)ArraysEasySolve
- Deduplicate Array by IterateeArrays & IterablesMediumSolve
Client-side Async & URL Handling
Parsing routing state, URL parameters, and resilient network requests with timeouts and automatic retries.
- Parse URL Query StringWeb APIs & UtilitiesMediumSolve
- Stringify Object to Query StringWeb APIs & UtilitiesEasySolve
- Promise with TimeoutAsync & PromisesEasySolve
- Retry Promise with Max AttemptsAsync & PromisesMediumSolve
Event-driven State & Caching
Constructing pub/sub communication busses, memoizing expensive computational renders, and deep cloning immutable data.
- Custom Event EmitterObject-Oriented / PatternsMediumSolve
- Implement MemoizeHigher-Order FunctionsEasySolve
- Deep Clone ObjectObjects & RecursionMediumSolve
Other Learning Paths
Full-Stack JavaScript
Conquer complex async control flow, concurrency limiters, background queues, LRU caching, and production backend debugging scenarios.
Senior TypeScript
Advanced functional currying/pipe/compose, immutability, structural typing, algorithmic invariants, and system code reviews expected of senior candidates.
JavaScript Core & Internals
The quintessential JavaScript fundamentals: prototypal methods (`bind`, `call`, `instanceof`), closures, array algorithms, and interview warmups.