karanpratapsingh/system-design

This repository is a comprehensive, free system design course covering the concepts that engineers are expected to know when designing large-scale distributed systems, and that come up repeatedly in technical interviews at software companies. The course is structured as a written guide rather than executable code. It starts from networking fundamentals such as IP addressing, the OSI model, and DNS, then builds up through application-layer protocols, database design patterns (SQL vs NoSQL, replication, sharding, ACID), caching strategies, message queues, and distributed systems theory covering availability, consistency, and the CAP theorem. From there it covers architectural patterns like microservices, event-driven design, and service meshes, and closes with walkthroughs of real-world system design problems of the kind asked in technical interviews. You would use this resource when preparing for senior engineering interviews where system design rounds are common, when onboarding to a new engineering role that requires understanding distributed infrastructure, or simply when you want a structured reference for the vocabulary and tradeoffs involved in building scalable systems. The material is self-contained and assumes programming knowledge but does not require prior distributed systems experience. The repository does not contain runnable software. It is a learning resource maintained as markdown documents. The language field in the repository metadata is unspecified because there is no source code, only written educational content.