I Built a Distributed Systems Simulator So You Don't Need Cloud to Learn Infrastructure

🚀 I Built a Distributed Systems Simulator So You Don't Need Cloud to Learn Infrastructure

Every tech company runs the same 6 layers:

🌐 Traffic Entry → Nginx, HAProxy, API Gateway
⚙️ Orchestration → Kubernetes, Nomad
🧩 Service Mesh → Envoy, Istio
🗄️ Data → PostgreSQL, Redis, MongoDB, Cassandra
📨 Messaging → Kafka, RabbitMQ, NATS
📊 Observability → Prometheus, Grafana, Jaeger

But learning these requires infrastructure. Multiple machines. Cloud accounts. Money.

I built DistSim to remove that barrier.

🧠 What It Does

DistSim runs on your laptop. Each "machine" is a real Ubuntu container. You get:

🖥️ Visual canvas to create and connect machines
💻 Real terminals, SSH into any machine from your browser
📦 22 installable services from Nginx to Vault
🧑‍💻 Built in code editor for Go, Node.js, Python
💥 Chaos engineering to inject failures and watch degradation
🧪 API tester to send requests and run load tests

🏗️ Example: Build a Load Balanced System

1️⃣ Create a lab with the "Medium Company" template
2️⃣ You get 1 load balancer, 3 app servers, database, Redis, 3 Kafka brokers
3️⃣ Install Nginx on the LB and configure upstream round robin
4️⃣ Write a Node.js API on each app server
5️⃣ Set up PostgreSQL replication
6️⃣ Send 1000 requests through the load balancer and watch distribution
7️⃣ Kill one app server and Nginx routes around it
8️⃣ Add 500ms delay to database and watch response times spike
9️⃣ Add Redis caching and watch response times drop

All of this happens on localhost. No cloud. No cost.

⚡ Install

git clone https://github.com/hamidlabs/distsim.git
cd distsim && bash install.sh

Auto starts. Open http://localhost:3000

Manage:

distsim stop
distsim start
distsim status
distsim logs

🧱 Tech Stack

🟦 Backend → Go, chi router, Docker Engine API
🟪 Frontend → Next.js, React Flow, xterm.js, Monaco Editor
🟨 Containers → Docker, each machine is Ubuntu container
🟩 State → Zustand frontend, in memory backend

🔮 What's Next

💾 Persistent sessions that survive restart
🎯 Guided challenges like payment service failure recovery
☸️ Kubernetes simulation mode
👥 Collaborative labs with teammates

⭐ GitHub: https://github.com/hamidlabs/distsim 🚀

If you are learning distributed systems, preparing for system design interviews, or teaching infrastructure, give it a try.
Stars and feedback welcome 🙌