Interview prep
Structured notes for system design interviews — clear concepts, worked examples, and fast revision before your round.
Patterns, complexity, and problem-solving frameworks.
Classes & APIsElevator, parking lot, LRU cache, and classic OOP designs.
Building blocksQueues, caching, CAP, sharding, sagas, and news feed.
Full designsInterview framework plus URL shortener, chat, payments, and more.
Deep divesOffline mirror — patterns, technologies, and problem breakdowns.
ExternalCurated sheets, roadmaps, company prep, and mock tests.