Simulation Hub
System Design Simulations
Fifteen interactive simulations of real architectures. Set the load, break a dependency, and watch latency climb and queues overflow — every module runs a live model instead of showing you a static diagram.
Foundations
Start here if system design is new. Each simulation builds the vocabulary the rest of the hub assumes.
Introduction to System Design — Interactive Simulation
Learn the fundamentals of system design through interactive visual simulations. Understand components, trade-offs, and scaling strategies.
Capacity Planning for System Design — Interactive Simulation
Master capacity planning with interactive simulations. Learn RPS, storage, bandwidth, and scaling calculations for production systems.
How Systems Scale — Interactive Scaling Simulation
See how systems evolve from a single server to millions of users. Interactive step-by-step architecture evolution with live simulations.
System Design Simulations
Full architectures for the products you already use, each one a simulation you can drive rather than a diagram you read.
URL Shortener System Design — Interactive Simulation
Learn URL shortener system design with interactive architecture simulations. Covers caching, hashing strategies, database sharding, and high-traffic scaling.
WhatsApp System Design — Interactive Simulation
Learn WhatsApp system design with interactive simulations. Covers real-time messaging, WebSockets, message queues, media delivery, and global scale.
Twitter System Design — Interactive Simulation
Learn Twitter system design with interactive architecture. Covers feed generation, fanout, timeline service, and handling millions of tweets per second.
Instagram System Design — Interactive Simulation
PROLearn Instagram system design with interactive simulations. Covers media upload, CDN delivery, feed ranking, and scaling to billions of users.
Dropbox System Design — Interactive Simulation
PROLearn Dropbox system design with interactive architecture. Covers file chunking, sync service, delta sync, conflict resolution, and distributed storage.
YouTube System Design — Interactive Simulation
PROLearn YouTube system design with interactive simulations. Covers video upload, transcoding pipeline, CDN streaming, and serving billions of daily views.
Uber System Design — Interactive Simulation
PROLearn Uber system design with interactive architecture simulations. Covers location tracking, driver matching, trip service, and real-time geospatial queries.
Payment System Design — Interactive Simulation
PROLearn payment system design with interactive architecture simulations. Covers idempotency, ledger service, webhook handlers, reconciliation, and financial reliability patterns.
Netflix System Design — Interactive Simulation
PROLearn how Netflix serves 260 million subscribers — Playback Service, ABR streaming, Open Connect CDN, upload transcoding pipeline, Watch History, and Recommendation Service. Full end-to-end interactive architecture.
Google Search System Design — Interactive Simulation
PROLearn how Google Search serves billions of queries per day — Query Processor, Search Coordinator, Index Shards, Ranking Service, Web Crawler, Inverted Index, and Autocomplete pipeline. Full end-to-end interactive architecture.
Architecture Decisions
Scenario-driven simulations of the judgement calls — which database, which consistency model, which failure to tolerate.
Choosing a Database — SQL vs NoSQL Simulation
PRONavigate 7 layers of engineering tradeoffs to discover which database fits your system. Interactive scenario-driven decision engine covering relational, document, graph, time-series, key-value, column-family, and search databases.
Distributed Systems Simulation — CAP, Consensus and Replication
PROUnderstand how distributed systems evolved — retries, idempotency, backpressure, replication, CAP theorem, quorum, consensus, and event-driven architecture explained clearly.
Every simulation is free to open and read. Sign in to run the interactive models, save your own architectures, and track progress across modules.
Start with the free simulations →