How to Design a System Like Instagram
A 19-step interactive guide to six Instagram-scale outcomes: media uploads, feed generation, bounded cache recovery, Reels ranking, direct messaging, and live delivery.
Interactive knowledge visualizations and simulators
Visualize Technology
Like Never Before
Explore complex technology concepts through runnable visualizations, failure-mode simulators, and cause-and-effect models.
Featured Visualizations 6 visualizations
gRPC over HTTP/2 Visual Walkthrough
Step through how a gRPC call moves from a local client method to Protobuf bytes, HTTP/2 frames, streams, trailers, deadlines, retries, and HPACK compression.
ACID Transactions Visualization
Step through the four ACID guarantees — Atomicity, Consistency, Isolation, Durability — with undo/redo logging, 2PL and MVCC isolation, isolation levels, and ARIES crash recovery.
API Pagination
Learn API pagination patterns. Compare offset, keyset, and cursor pagination query costs and learn how drift anomalies occur.
API Security Visualization
Explore a 13-step API security visualization covering TLS, OAuth2/OIDC, API gateways, rate limiting, WAF filtering, validation, tokenization, CORS, safe errors, and centralized audit trails.
API Testing Types and Strategies
Explore an 11-step API testing visualization that shows how smoke, functional, integration, regression, load, stress, security, penetration, fuzz, and resilience checks protect an API.
Featured Simulators 4 simulators
ACID Isolation Locking Lab
Simulate a checkout race to see how ACID isolation, row locks, table locks, MVCC snapshots, range locks, and serializable retries keep database state correct.
Auto-Scaling (HPA) Simulator
Simulate Kubernetes Horizontal Pod Autoscaler scaling pod replicas based on CPU utilization. Watch pods spin up and down as traffic changes, experiment with scaling thresholds
Auto-Scaling Component Runtime Simulator
Test Kubernetes HPA autoscaling as explicit runtime components with parent-owned input ports, child injection, routed connector messages, component state, element state, controls
B-Tree Indexing Enhanced Simulator
Test database B-Tree indexing as explicit runtime components with parent-owned input ports, child injection, routed connector messages, buffer pool caching, and query planning.
How It Works
Learn by exploring systems directly, not by reading static diagrams
1
Pick a Guide
Browse a curated catalog of technology concepts, from distributed consensus to infrastructure failure modes.
2
Open the Experience
Launch a live visualization or simulator directly in the browser. Each entry includes context, scenarios, and model notes.
3
Experiment
Change parameters, trigger events, inspect entities, and watch the system respond in real time.