Is the system design simulator free?

Yes, the VisualCoders System Design Simulator is free to use. You can access the drag-and-drop canvas, run traffic simulations, and attempt scenario challenges at no cost. An account is required to save your designs to the cloud.

What system design topics does the simulator cover?

The simulator covers the full range of distributed systems components — load balancers, API gateways, databases (SQL and NoSQL), caches (Redis, Memcached), message queues, CDNs, microservices, reverse proxies, service meshes, and more. Scenarios range from URL shorteners to real-time chat apps and video streaming platforms.

Can I use this to prepare for FAANG system design interviews?

Yes. The simulator is built specifically for system design interview preparation. It includes real interview-style scenarios asked at companies like Amazon, Google, Meta, and Microsoft. The traffic simulation and failure injection features help you reason about trade-offs — exactly what interviewers look for.

Does the system design simulator work for beginners?

Absolutely. Beginner scenarios like URL Shortener and Notification Service walk you through foundational concepts with step-by-step hints. You can start the simulator with zero prior system design knowledge and progressively tackle more complex scenarios as your understanding grows.

What is the difference between beginner and expert scenarios?

Beginner scenarios involve 3–5 components and focus on single core concepts (hashing, caching, basic scaling). Expert scenarios involve 10+ components, require reasoning about consistency vs. availability trade-offs, handle millions of requests per second, and expect you to design for failure, geo-distribution, and data partitioning.

🎯

System Design Interview

Choose a scenario below. You will have 45 minutes to design the system, with phase-based prompts guiding the interview format.

⏱Interview duration: 45 minutes·5 interview phases·3 hints available

Loading interview…

🎯

System Design Interview

Choose a scenario below. You will have 45 minutes to design the system, with phase-based prompts guiding the interview format.

⏱Interview duration: 45 minutes·5 interview phases·3 hints available