FlowFrame

FlowFrame

Distributed System Simulator

FlowFrame

See your backend architecture run.

FlowFrame simulates distributed system patterns — load balancing, caching, API gateways — and plays them back frame by frame. Not just diagrams. Actual running logic you can pause, inspect, and learn from.

EngineersSystem Design learnersTech intervieweesEducators

v2.0.0 — FlowFrame DSL Engine + Monaco Code Editor · API Gateway, Load Balancers, RabbitMQ & PubSub Brokers · 8 Component Nodes

Live simulation preview Running

Round Robin · 3 servers · Real engine output

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⚡ FlowFrame DSL (.flow) — Declarative architecture compiler & engine💻 Monaco Code Editor — Real-time syntax highlighting & autocompletion🚪 API Gateway — Path-based routing to Server & LoadBalancer clusters⚖️ Load Balancing — Round Robin & IP Hash traffic distribution📬 RabbitMQ Queue — Asynchronous message buffering & consumer prefetch📢 PubSub Broker — Multi-subscriber event fan-out & topic channels🗄️ Cache-Aside — Redis hit/miss & PostgreSQL database fallback📖 Interactive Docs (/docs) — FastAPI-style comprehensive language reference⚡ FlowFrame DSL (.flow) — Declarative architecture compiler & engine💻 Monaco Code Editor — Real-time syntax highlighting & autocompletion🚪 API Gateway — Path-based routing to Server & LoadBalancer clusters⚖️ Load Balancing — Round Robin & IP Hash traffic distribution📬 RabbitMQ Queue — Asynchronous message buffering & consumer prefetch📢 PubSub Broker — Multi-subscriber event fan-out & topic channels🗄️ Cache-Aside — Redis hit/miss & PostgreSQL database fallback📖 Interactive Docs (/docs) — FastAPI-style comprehensive language reference

What makes it different

Not a diagram tool.
A running system.

Most system design tools let you draw boxes and arrows. FlowFrame actually runs the logic, captures every hop, and plays it back so you can see what's happening inside.

⚡

Run real simulations

The engine actually runs your distributed system. Requests hop from Client → Load Balancer → Server → Redis → Postgres — not just drawn arrows.

🎞️

Frame-by-frame playback

Every request hop becomes a playback frame. Pause at any moment, scrub backwards, or fast-forward. See exactly what happened and why.

🔬

Inspect node state

Open any node's inspector. See Redis key snapshots, server load, capacity, request queues — all updating live as the simulation runs.

📚

Learn as you simulate

Each concept has a guided doc page with a live sim embedded. Read the theory, trigger the failure, watch the recovery — all on one screen.

Supported in v2.0

v2.0.0 RELEASE

Pick a scenario. Hit play.

Each scenario is pre-wired with real engine logic. Just select one and watch the architecture run.

⚖️
v2.0 · Live

Load Balancing

Watch Round Robin and IP Hash distribute requests across 3 servers. Drag capacity to 0 to see failover in action.

Round RobinIP HashFailover
Open Simulator→
🗄️
v2.0 · Live

Cache-Aside

Three deterministic requests: cache hit, cache miss → DB fallback, and invalid key. See Redis snapshots update frame-by-frame.

Redis Hit/MissDB FallbackTTL
Open Simulator→
🚪
v2.0 · Live

API Gateway

Path-based routing with server & LoadBalancer pools. Set a server's capacity to 0 and watch gateway failover.

Path RoutingLoadBalancer Target503 Failover
Open Simulator→
🔑
v2.0 · Live

Valet Key Pattern

Client requests a signed upload token from the server. Server issues it. Client uploads directly to cloud storage — no proxy.

Token IssuanceDirect UploadCloud Storage
Open Simulator→
📖

FlowFrame DSL Docs

Explore language specifications, syntax rules, schema specs for all 8 component nodes, and copy-pasteable flagship architecture scripts.

Read DSL Docs (/docs) →
📚

Guided Scenarios

Guided learning for each distributed system concept — theory on the left, live simulation on the right.

Start Scenarios →
⚡

Monaco DSL Sandbox

Write code in Monaco Editor using FlowFrame DSL or drag & drop nodes on canvas. Run live system simulations instantly.

Open Workspace →
Version 2.0.0

What's supported right now in v2.0

✓ Supported

  • ✓FlowFrame DSL (.flow) Interpreter Engine
  • ✓Monaco Code Editor with Syntax Highlighting & Autocompletion
  • ✓Client -> API Gateway -> LoadBalancer -> Server Topology
  • ✓Message Queue (RabbitMQ FIFO) Producer/Consumer Simulation
  • ✓PubSub Broker Event Fan-Out & Custom Server Topic Registration
  • ✓Round Robin & IP Hash load balancing
  • ✓Capacity-based server failover
  • ✓Cache-Aside pattern (Redis)
  • ✓Database fallback (Postgres)
  • ✓API Gateway path routing with LoadBalancer targets
  • ✓Valet Key token issuance & Cloud Storage uploads
  • ✓Frame-by-frame traffic playback
  • ✓Node state inspector & health overlay
  • ✓Custom sandbox canvas with JSON import/export

⏳ Coming next

  • ○More LB strategies (Least Conn, Weighted RR)
  • ○Circuit Breaker & Retry patterns
  • ○Distributed Tracing (OpenTelemetry style visualization)
  • ○Kafka Partitioned Log simulations

Ready to see your architecture run?

Pick a scenario, hit play, and watch every hop of every request — live.