Deep dives into system design, software patterns, concurrency and algorithms — with annotated code, diagrams, and the tradeoffs an interviewer will actually push on.
Distributed systems, microservices, and large-scale architecture patterns.
OOP principles, design patterns, and class diagrams for real-world systems.
350+ hand-picked problems across arrays, trees, graphs, and DP — organized into curated playlists.
Threads, locks, async patterns, and parallel computing fundamentals.
A structured decision framework for choosing the right database — SQL vs NoSQL, CAP thinking, NoSQL types, and interview-ready justification templates.
Low-level design of an expense-sharing app — user and group management, three split strategies (equal, percentage, exact), Factory pattern for entity creation, Singleton orchestration, and a Facade that hides all internal complexity.
Covers: Data structures Used, If path is needed. Optimal — Time O( (E+V), Space O( |V| ).
A progressive, hands-on workbook for building stream-writing fluency from scratch. Six levels, basic → advanced — write every exercise from a blank page.
The essential reference for system design interviews — powers of two, latency numbers every engineer should know, and availability nines decoded.
A complete low-level design walkthrough for Amazon Locker — from requirements clarification to token-based access, compartment management, and expiry enforcement in Java.
Covers: Dijkstra's Algo, Floyd warshall's. Optimal — Time O(n^3), Space O(n^2).