System Design Practice Tests: 600+ MCQs & Interview Prep

Struggling to explain how you'd design Twitter, a URL shortener, or a real-time chat app in an interview? This course gives you 600 carefully-explained practice questions covering the entire system design interview landscape, organized into six progressive practice tests. You'll start with the fundamentals: horizontal and vertical scaling, load balancing, caching strategies, and resilience patterns like circuit breakers and rate limiting.

From there, you'll move into databases and storage — SQL vs. NoSQL tradeoffs, indexing, replication, sharding, and modern storage engines. The third test tackles distributed systems concepts head-on: the CAP theorem, consensus algorithms like Raft and Paxos, distributed transactions, and eventual consistency.

Test four covers messaging and event-driven architecture, including message queues, pub/sub, event sourcing, CQRS, and the Saga pattern. Test five is where it all comes together: full worked case studies for real systems like URL shorteners, social media feeds, chat applications, ride-sharing dispatch, and payment systems. The final test covers microservices architecture, API design, and reliability patterns you'll need for senior-level interviews.

Every question includes detailed explanations for all four answer choices — not just the correct one — so you understand the reasoning, not just the answer. Concepts build on each other across tests, reinforcing what you've learned while introducing new material. Whether you're a new grad preparing for your first system design round or an experienced engineer targeting a senior or staff position, this course will build the deliberate, tradeoff-aware thinking that system design interviews are actually testing for.