I’ve been hacking on a side project: a web-based “System Design Simulator.” It’s like a whiteboard, but you can actually press play and watch your architecture behave (or fail). What you can do: Drag-and-drop common pieces: load balancer, API gateway, caches, DBs, queues, even some AI bits. Hit “Start Simulation” to see latency, error rate, throughput, cache hit rate in real time. Flip chaos switches: traffic spikes, cache-miss storms, network partitions, component crashes. Share & remix: every design gets a short link; anyone can fork it and improve. Built-in hints: it tells you if you forgot an entry point or storage. Why I made it: Diagrams don’t fail; systems do. I wanted a fast way to feel trade-offs without spinning up infra. For interviews and design reviews, it’s nice to ask “what if the cache dies?” and just click a button.

paperdraw.dev

An Early Warning System for Your Architecture.

An Early Warning System for Your Architecture.