System design stopped being theoretical. You can now simulate traffic spikes, kill caches mid-request, and watch cascading failures happen on screen before writing any code.

The gap between "whiteboard architecture" and "production reality" just got a tool that sits right in the middle. Build it visually, break it intentionally, fix it before deploy.

If you've ever drawn boxes and arrows on Excalidraw and wondered "but will this actually work under load?" ... now you can find out.