Free Course 15 lessons
System Design Course: 15 Lessons From Real Outages
Start here. Story-driven lessons with diagrams from request paths to interview playbooks, built from production postmortems.
System Design & Architecture Case Studies
Production post-mortems, trade-off evaluations plus counterfactual redesigns.
Start here: Browse 13 system design postmortems with RPS and cost models plus 6 AI slop incident files. Each teardown shows what broke and what should be, with math you can run.
1M+ RPS
Telemetry Ingestion
99.99%
Production Availability
5+ Yrs
Go & Cloud Infra
< 50ms
State Sync Latency
New shelf
AI Slop Watch: incident files from the frontier. Breakouts, buyouts, plus picker fights. Browse the shelf.
RFCs & Deep Dives
Control Plane Infrastructure September 2026
etcd: The Handshake That Never Ends
CVE-2026-73500 lets silent TLS connections exhaust etcd memory and take down the Kubernetes control plane. Handshake math plus deadlines.
Messaging Infrastructure September 2026
Discord: Trillions of Messages, 177 Nodes Too Many
Hot partitions, quorum amplification and JVM pauses across 177 Cassandra nodes, ended by a Rust layer plus 72 ScyllaDB nodes.
Event Infrastructure September 2026
Kafka Rebalance Storm: One Rolling Deploy Paused Every Consumer
A modeled teardown of consumer-group rebalance cascades, coordinator assignment math across 40,000 partitions plus 6x retry amplification.
Developer Tools September 2026
Cursor and Claude Code Postmortem: The Token Meter Is the Real Pair Programmer
A forensic teardown of token limits, context rot, compaction cliffs, productivity math and the fixes vendors keep postponing.
AI Infrastructure September 2026
Perplexity Postmortem: The Answer Engine That Pays for Every Question Twice
A forensic teardown of RAG retrieval, KV cache reuse, prefill cost plus inference economics at scale.
Cloud Infrastructure September 2026
Simultaneous AI Model Outage: The Single Point We All Ignored
A failure analysis of a shared dependency beneath multiple frontier AI providers and the resilience lessons.
Agent Runtime September 2026
Replit Agent Postmortem: The Day the Demo Became Production
A teardown of sandbox execution, agent retries, deployment risk plus prompt-to-production infrastructure.
Cloud Infrastructure September 2026
Vercel Fluid Compute: The Serverless Bill Was Waiting for a Response
A system design analysis of concurrency, cold starts, provider wait time plus serverless cost controls.
Realtime Systems September 2026
Figma's Multiplayer Editor: The Server That Decides Who Wins
A practical teardown of WebSocket collaboration, server-authoritative conflict resolution plus realtime cost.
Forensic Architecture August 2026
The Workspace That Ate the Warehouse
A data-platform teardown covering PostgreSQL sharding, CDC, Kafka, object storage, vector search plus modeled cloud cost.
Architectural Critique July 2026
Rethinking Control Planes: Cell-Based Architectures for Zero-Blast Radius
An analysis of regional isolation, failure containment, Raft-backed cells plus zero-blast-radius operations.