Ask "design a rate limiter" or "push vs pull for a celebrity feed?" and get the frameworks, trade-offs, and numbers you need — routed to the right material, on demand.
A Claude Code plugin that puts system-design interview frameworks at your fingertips while you work. The 4-step method and core mental models load instantly; deeper topics and full system walkthroughs load only when you ask.
Important
Study aid, not a substitute for the book. Every concept here originates from Alex Xu's System Design Interview — An Insider's Guide (Vol. 1 & 2). If this is useful to you, buy the books and support the author: https://bytebytego.com.
/plugin marketplace add v11g/system-design-skill
/plugin install system-design@system-design-skill
Then invoke it any time with /system-design, or just ask a system-design question and the skill activates.
Manual install (no marketplace)
git clone https://github.com/vukhanhtruong/system-design-skill.git
cp -r system-design-skill/skills/system-design ~/.claude/skills/| Situation | What it gives you |
|---|---|
| Interview prep | The 4-step framework, estimation numbers, and 28 worked designs to practice against |
| Early architecture thinking | "Shard or replicate?" "Push or pull?" "CP or AP?" — the trade-off and why |
| Learning a concept | Deep, on-demand explanations of consistent hashing, quorum, fanout, sagas, erasure coding… |
| Design review | Sanity-check your design against the book's patterns and surface failure modes |
| System templates | A starting blueprint for URL shortener, chat, payments, YouTube, S3, leaderboard, and more |
Not for: production configuration. It gives interview-altitude reasoning, not exact APIs, limits, or pricing. For real builds, pair it with current vendor docs (Redis, DynamoDB, Kafka, AWS…).
Browse / meta
what chapters do you have?
show me the core frameworks
what's in the cheatsheet?
Explain a topic — the skill finds and reads the right chapter
explain consistent hashing
how does fanout work?
token bucket vs leaking bucket
how do I get exactly-once delivery?
explain quorum W+R>N
saga vs TC-C vs 2PC
Design a system — full 4-step walkthrough
design a URL shortener
walk me through designing a chat system
design a Twitter news feed
design a payment system
Interview practice
run a mock interview: design a notification system
quiz me on the 4-step framework
back-of-envelope numbers for 100M DAU
what latency numbers should I memorize?
Decision / trade-off
shard or replicate for read-heavy load?
push vs pull for a feed with celebrities?
which rate-limit algorithm for bursty traffic?
CP or AP for a shopping cart?
Review your design
review my design: [paste] — what failure modes did I miss?
did I handle idempotency right in this payment flow?
- Core frameworks (instant): 4-step method, back-of-envelope estimation, scaling spine, CAP + quorum, consistent hashing, fanout, rate limiting, money/correctness, queues & streaming.
- 28 chapter summaries (on demand): from rate limiter and KV store to payment systems, digital wallets, and a stock exchange.
- References: a glossary, a patterns file with trade-offs, and a decision cheatsheet.
All system-design concepts and frameworks are the intellectual property of Alex Xu (Vol. 2 with Sahn Lam) and ByteByteGo. This repository contains independently written summaries and original structuring intended as a personal/educational study companion under fair-use principles. It does not include the book's text verbatim, its figures, or its diagrams.
If you are a rights holder with a concern, please open an issue or contact the maintainer — disputed content will be removed promptly.
See NOTICE for full attribution and LICENSE for the terms covering this plugin's original scaffolding and code.