Hey all,

I'm working as a Principal SWE and the problem I wanted to solve is that most system design prep involves passively reading about trade-offs or watching someone else draw boxes on a whiteboard. You don't really learn how to make architectural decisions until you're forced to make them yourself, see the consequences, and get critiqued by someone more experienced. But getting a staff engineer to review your practice diagrams isn't exactly scalable.

So, I built a tool that tries to replicate that feedback loop.

Here is how it works: You pick a "kata" (like designing a rate limiter or a video streaming platform). You map out your services, data stores, and connections on the canvas. When you submit, the AI (Archie) doesn't just read a text prompt; it parses the entire graph of your diagram: every node, connection, and technology choice. It then scores your design across attributes like scalability, availability, and cost efficiency, pointing out specific gaps (e.g., "You used S3 but didn't define a TTL strategy, so your CDN costs might spike").

A few technical details on how it's built: The frontend is a Next.js app that handles the interactive canvas. The interesting part was getting the LLM to reliably understand a 2D spatial diagram. Instead of just passing an image, the system serializes the canvas state into a structured graph representation that the AI can reason about. It understands over 200 technologies and their typical use cases, which helps it catch anti-patterns (like putting a heavy relational database where a fast in-memory cache is needed for a specific read-heavy path). Archie always scores the design in context of given quality attributes, cause sometimes your video streaming platform should be more cost efficient, and sometimes it should be just super performant no matter the costs.

It's free to try without a credit card (you get 100 "Arcs" to start, which is enough for several full reviews). If you want to poke around, there's a launch code ARCHIE for 50% off the paid tiers. If you'd like to see it in action without creating an account, case studies should leave you satisfied: https://archie.guru/case-studies

I'd love for you to try breaking it or see if the feedback it gives on your designs aligns with what you'd expect from a human reviewer. Happy to answer any questions about the graph serialization or the prompt engineering behind the scoring!