Open SystemDecoder on a larger screen to build systems, run simulations, and inject chaos.
What's waiting for you on desktop
Live Simulations
Watch latency spike, queues fill, and nodes fail in real time. Every slider change is instant.
Visual Architecture Canvas
Drag nodes, draw edges, and build any distributed system topology from scratch.
Chaos Engineering
Kill servers, introduce packet loss, throttle CPUs — and watch your system react.
Real-time Insights
Throughput, p99 latency, error rates — all charted live as your simulation runs.
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Replays
"The best way to understand a distributed system
is to break it."
Dropbox
📦
700M users. Exabytes of files.
Save on laptop → appears on phone in seconds
Dropbox has 700 million registered users and stores exabytes of data. When you save a file on your laptop, it appears on your phone in seconds. How does the system split, store, and synchronise billions of files reliably?
Why We Need This
You'll build Dropbox's architecture step by step — from a naive API-to-DB approach that breaks on large files, all the way to a chunked, blob-stored, CDN-delivered, multi-device sync system.
Key Insight
The core insight: separate file bytes (blob storage) from file metadata (relational DB), split large files into small chunks, and use an event-driven sync pipeline to propagate changes across devices.
Overview