Full-Stack JavaScript
Conquer complex async control flow, concurrency limiters, background queues, LRU caching, and production backend debugging scenarios.
Curriculum Phases(4 phases · 18 problems)
Promise Combinators & Sequential Flow
Rebuilding the core JS Promise ecosystem from scratch: parallel aggregations, race conditions, and sequence runners.
- Implement Promise.allJavaScript AsyncMediumSolve
- Implement Promise.allSettledJavaScript AsyncMediumSolve
- Implement Promise.anyAsync & PromisesMediumSolve
- Implement PromisifyAsync & PromisesMediumSolve
- Execute Async Tasks in SequenceAsync & PromisesMediumSolve
Concurrency Limiters & Resilient Queues
Preventing socket exhaustion and API rate limits using sliding concurrency windows, exponential backoff, and batch queues.
- Implement Concurrency LimiterAsync Control FlowHardSolve
- Async Map with Concurrency LimitAsync & PromisesHardSolve
- Exponential Backoff RetryAsync & PromisesHardSolve
- Batched Async Task QueueEvent Loop & TimersHardSolve
In-memory Caching & Deep Objects
High-performance O(1) eviction caches, deep merge pipelines, structural equality checks, and safe JSON parsing.
- LRU CacheSystem & Data StructuresMediumSolve
- Deep Merge ObjectsObjects & ImmutabilityMediumSolve
- Deep Equality ComparisonJavaScript UtilitiesMediumSolve
- Set Nested Property by PathObjects & ImmutabilityMediumSolve
- Safe JSON Parser (No Throw)Web APIs & UtilitiesEasySolve
Production Diagnostics & Code Review
Identifying backend connection leaks, unhandled promise rejections, N+1 query explosions, and listener leaks in real pull requests.
- Code Review: Promise Concurrency ExhaustionAsync & ConcurrencyMediumSolve
- Code Review: N+1 Database QueriesDatabase & PerformanceMediumSolve
- Code Review: Node.js Memory LeakNode.js & MemoryHardSolve
- Event Emitter with .once() and Listener CountDesign PatternsMediumSolve
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.
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.