#simulation

Curated list of visual programming tools and cloud simulators for prototyping and simulating IoT devices and flows.

200Lab's free browser game at systemdesign.200lab.io. You place components, the server simulates the traffic, and a level passes only inside its success, latency, and budget limits, with up to three stars for a cheaper design.

Syscraft is Nguyen Thanh Minh's hosted system design lab at syscraft.app: draw an architecture, run simulated traffic, and pass graded challenges. Checked 2 November 2026 without an account: the marketing page lists 7 topics and Pro at $9 a month through Lemon Squeezy, while the learn index lists 42 lessons and the challenge index lists 19.

MIT discrete-event system design simulator at breakscale.tech (workersio/breakscale). The browser, the VS Code webview, and the MCP server share one engine: 33 node kinds, 23 presets, and four challenges. Checked 2 November 2026: 1,953 stars, share links seal designs with AES-GCM and keep the key in the URL fragment, and the website also loads Vercel Analytics.