System Design Sheet
The System Design sheet lays out the building blocks a system design interview actually tests — how data is stored, replicated, cached, queued and kept consistent — and pairs each with case studies and interview practice.
The sheet holds 12 patterns and 73 topics, tracked row by row. From any row you can read the theory for a topic, sit a mock interview on it, design it on a whiteboard, have the AI coach teach it back to you, keep notes, bookmark a row and mark it done. Progress is saved against your account, so the sheet is also the record of what you have already covered.
Looking for the course? System Design course teaches the same families as theory and lessons, rather than a progress checklist.
Who it is for
It is aimed at engineers with production experience preparing for a senior or staff loop, and at anyone who can describe a service they have shipped but freezes when asked to size it or defend a trade-off.
How to work through it
Study a pattern, then immediately design something with it out loud. A design you can only recognise is not a design you can defend for forty-five minutes, and the interviewer is grading the defence.
Practice runs on the same platform as the sheet: 850+ problems across every track, code execution in 6 languages, and AI mock interviews that follow the pattern you are studying rather than a random question.
What the system design sheet covers
Interview Soon (~20h)
8 patterns that cover 80% of system design interviews
- Foundations — The 45-Minute Framework, Estimation & Modern Numbers, CAP & Consistency, Availability & SLA Math, Latency & Capacity Planning, Design URL Shortener
- Networking & APIs — Protocols, API Design, gRPC Deep Dive, Advanced API Patterns, Design WhatsApp Chat
- Databases — SQL vs NoSQL, Replication & Sharding, Indexing & Storage, LSM Trees & WAL, Specialized Storage, Design a Key-Value Store, Design Dropbox
- Caching — Cache Strategy, Cache Failure Modes, Multi-Layer Caching, Design Rate Limiter, Design a Distributed Cache
- Queues & Async — Queue Fundamentals, Delivery Guarantees & Idempotency, Event-Driven Patterns Deep Dive, Kafka Deep Dive, Stream Processing, Design YouTube, Design a Webhook Delivery System, Design a Notification System, Design a Web Crawler, Design a Job Scheduler
- Scalability — Consistent Hashing, Scaling Reads vs Writes, Service Architecture Deep Dive, Design Twitter Feed, Design URL Shortener at Massive Scale, Design Instagram, Design TikTok Feed
- Coordination & Transactions — Consensus & Locking, Distributed Transactions, Raft Deep Dive, Gossip & Quorum, Design Ticketmaster, Design Payment System, Design Ticketmaster at Scale, Design Google Docs, Design a Stock Exchange
- Search, Geo & Aggregation — Search & Geospatial, Real-Time Aggregation, Elasticsearch Deep Dive, Probabilistic Structures Deep Dive, Design Uber, Design an Ad Click Aggregator, Design Uber Deep Dive, Design a Top-K Leaderboard, Design Google Maps
Deep Dive (~60h)
4 patterns for deep expertise and senior-level interviews
- Reliability & Operations — Monitoring & Observability, Deployment & Failure Handling
- Security & Auth — Authentication, API Security
- AI Infrastructure — LLM Serving (Design ChatGPT), Inference Batching, RAG Pipeline, Vector Search at Scale, Distributed Model Training, Design a Recommendation System
- Real-World Architecture Studies — Discord — Trillions of Messages, Uber — Real-Time Matching, Stripe — Payment Infrastructure, Netflix — Video Delivery, Kafka Internals
