Web-based System Design Simulator released
A new web System Design Simulator lets users drag-and-drop components like API gateways, DBs and caches and then simulate real-time traffic, latency and failures to validate architecture choices. It’s a practical way to rehearse trade-off conversations that typically come up in interviews. (x.com)
paperdraw.dev — a browser-based System Design Simulator by Pratap Vhatkar — was published as a demo post on Mar 10, 2026 and is available as an interactive web app at paperdraw.dev. (dev.to) The tool generates short, shareable links for every design and lets anyone fork/remix a scenario, giving each design a persistent URL for collaboration. (dev.to) Built-in simulation telemetry reports live throughput, latency, p99/p95 behavior, cache-hit rates and error-rate metrics while a scenario runs, and the UI exposes chaos toggles for traffic spikes, cache-miss storms, network partitions and component crashes. (dev.to) The author posted a short demo video showing animated request flows and failure injection; the video accompanies the release and solicits user feedback on realism and presets. (youtube.com) The release drew attention on Hacker News where early comments noted the simulation visuals and realism, and the project was picked up in community threads as a hands-on alternative to static architecture diagrams. (news.ycombinator.com) The developer lists follow-ups on the project roadmap — presets for payment/chat/ingestion scenarios, export GIFs, and UX tweaks — and explicitly asks the community for feature suggestions and bug reports. (dev.to)
