1582 articles
Build an LRU Cache from scratch using a doubly linked list with sentinel nodes and a HashMap for O(1) get and put operations. The most frequently asked hard design problem at Amazon, Microsoft, Google, and Facebook — explained step by step with diagrams.
Implement a browser history data structure with visit, back, and forward operations using a doubly linked list for O(1) navigation. A practical design interview problem at Amazon, Microsoft, and Google that tests your ability to model real-world state with linked list pointers.
LC 28 Find the Index of the First Occurrence in a String is the canonical KMP problem at Google, Meta, and Amazon. Build the failure function in O(m), search in O(n), and never re-examine a matched character again.
Master MongoDB with Node.js and TypeScript using both the native driver and Mongoose ODM. Covers CRUD, aggregation, transactions, indexing, and production patterns.
Build production-grade full-text search with Elasticsearch and TypeScript. Covers indexing, querying, aggregations, analyzers, and scaling patterns for Node.js backends.