FlowFrame - Build, configure, and visually understand distributed system

Most system design resources show architectures as static diagrams. I wanted to build something where you can actually create an architecture, configure it, run it, and understand what happens inside the system. FlowFrame is an interactive system design simulator and learning environment built around that idea. With FlowFrame, you can: Create workspaces and multiple system diagrams Build architectures using an interactive canvas Configure components and their behavior Define architectures using the FlowFrame DSL Learn the DSL through its syntax and rules Run REST API requests through your architecture Play, pause, and step through simulations Visualize request and packet flows Run multiple requests simultaneously Inspect system events, cache hits, database operations, routing, and queues Explore Load Balancers, API Gateways, Servers, Redis, PostgreSQL, Connection Pools, Message Queues, Pub/Sub, Workers, and more Experiment with FIFO, LIFO, and Priority queue processing Explore caching, load balancing, database pooling, microservices, monoliths, and event-driven architectures Work through guided system-design scenarios with validation Learn distributed-system concepts through a searchable glossary Import and export architectures Save and share system designs Use the Demo Sandbox without signing in The goal is simple: Instead of only looking at a system design diagram, build it, run it, and see how it behaves. FlowFrame focuses on making the logical behavior of distributed systems easier to understand through experimentation and visualization. I'm still building and expanding it, so I'd love to know: What distributed-system concept, architecture, or failure scenario should I add next?