My side project just passed 100 GitHub stars: system design diagrams that tell you if the design would hold up

Most architecture diagrams are just pictures. You can't ask one, "will this hold at 5k requests a second?" I built Proschi so you can. You write your system as text. It draws the diagram, plays each request step by step, and simulates load, latency, availability, and cost. Your requirements can fail, like tests: db "Orders DB" [PostgreSQL] x1 requirements { survive any node failure } With one database replica, that goes red. Change x1 to x2 , and it passes (it's important that it's just an example; you can go further and define SLAs, HA, RPS, etc.) New in the latest release: I've scaled up the proschi diagrams even further; now you can connect multiple HLDs in one. i.e., if you depend on another team, you don't have to assume which components they have internally, but you can simply connect your architecture to theirs! Also, you can check whether your new feature will affect them. Free and open source (MIT), runs in your browser. It compares designs from default numbers, so it doesn't measure your real system. proschi.app · GitHub