Data Structures

Learn caching strategies — cache-aside, write-through, TTL, eviction policies, and Redis vs Memcached.

Learn load balancer types, algorithms (round-robin, least connections), and health checks.

Understand vertical scaling (bigger machines) vs horizontal scaling (more machines) and when to use each.

Learn the fundamentals of system design — scalability, reliability, availability, and the design interview process.

Complete system design reference — key numbers to memorize, SQL vs NoSQL guide, the 6-step interview framework, and company-wise topic list.

10 real Python interview questions from Google, Amazon, Flipkart — GIL, decorators, generators, asyncio, shallow vs deep copy, and coding challenges.