JavaScript Core & Internals
The quintessential JavaScript fundamentals: prototypal methods (`bind`, `call`, `instanceof`), closures, array algorithms, and interview warmups.
Curriculum Phases(3 phases · 12 problems)
Prototypes & Function Context
Re-implementing the language's core invocation primitives: `Function.prototype.bind`, `call`, `apply`, and the prototype chain traversal.
- Implement Function.prototype.bindClosures & FunctionsMediumSolve
- Implement Custom Call and ApplyClosures & FunctionsMediumSolve
- Implement Custom instanceofPrototypes & OOPEasySolve
- Function Once WrapperClosures & FunctionsEasySolve
Array & Cookie Manipulation
Array intersection, difference sets, tuple pairing, and RFC-compliant HTTP cookie string parsing.
- Array DifferenceArrays & IterablesEasySolve
- Array IntersectionArrays & IterablesEasySolve
- Zip Arrays into TuplesArrays & IterablesEasySolve
- Parse document.cookie StringWeb APIs & UtilitiesEasySolve
Core Data Structures & Cancellable Timers
Two-pointer hash lookups, singly linked list reversal, cancellable timeout tokens, and truthy array compacting.
- Two SumArrays & HashingEasySolve
- Reverse Linked ListLinked ListsEasySolve
- Cancellable DelayAsync & PromisesEasySolve
- Compact Array (Remove Falsy)Arrays & IterablesEasySolve
Other Learning Paths
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.
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.