System Design for Builders
Most system design content is written for FAANG interviews, not for people shipping products. This course is different. Every concept is grounded in decisions you actually face: should I add a cache here? When do I need a queue? How do I structure this so it does not fall apart at 10,000 users? You will learn to reason about trade-offs, read load, and design systems that grow with your product without over-engineering them.
What you'll learn
Course outline
Free — no account needed
Full course — $89 one-time
Caching Strategies
Cut database load by 80% — cache-aside, write-through, TTL, and cache invalidation patterns
Queues and Async Processing
Move slow work off the request path — analytics, webhooks, AI inference, and background jobs
Data Consistency and the CAP Theorem
ACID vs BASE, eventual consistency, distributed transactions, and when Postgres is the right answer
API Design and Versioning
REST, RPC, and GraphQL — when to use each and how to version without breaking clients
Rate Limiting and Abuse Prevention
Token bucket, sliding window, Redis-based limits, DDoS patterns, and API key management
Load Balancing and Horizontal Scaling
Scale your app horizontally — stateless servers, sticky sessions, and auto-scaling patterns
CDN and Edge Architecture
Static vs dynamic caching, Cloudflare Workers, cache-control headers, and when to use edge functions
Observability and Reliability
Know when something breaks before your users do — logging, metrics, alerting, and SLOs
Incident Response and Postmortems
On-call fundamentals, runbooks, the 5-step incident process, SLAs, and blameless postmortems
System Design Patterns in Practice
Complete architecture review — every pattern applied, the next three bottlenecks, and what to build next
Get the full course
12 lessons — from the mental model through CAP theorem, rate limiting, CDN architecture, incident response, and a complete URL shortener architecture at 100M req/day.