System Design Notes

This repository collects study notes based on the System Design Interview - An Insider's Guide books (Volumes 1 and 2) by Alex Xu. It's aimed at engineers preparing for system design interviews, or anyone who wants a structured reference for common large-scale system design problems. Each chapter of the books gets its own folder with notes, and the repo links out to a rendered version hosted on Pagefy for easier reading.

The content follows the books closely: it starts with foundational topics like scaling and back-of-the-envelope estimation, then moves into concrete system designs such as rate limiters, key-value stores, URL shorteners, chat systems, and more advanced designs like a stock exchange or a distributed email service. Beyond summarizing the books, the author adds a curated list of external resources (engineering blog posts, academic papers, and talks) for topics like consistent hashing, key-value stores, and web crawlers, so readers can go deeper on specific subsystems.

Key features

• Chapter-organized notes: 28 folders, each mapping to a chapter from the System Design Interview books, from scaling basics to a full stock exchange design.
• Rendered reading experience: a hosted Pagefy site presents the notes in a cleaner, browsable format instead of raw markdown files.
• Curated external resources: links to primary sources like the Amazon Dynamo paper, Google BigTable paper, Discord and Slack engineering blogs, and Twitter's Snowflake announcement, grouped by topic.
• Broad topic coverage: includes both classic interview staples (rate limiter, consistent hashing, unique ID generator) and newer additions (payment systems, digital wallets, real-time gaming leaderboards).
• Free reference format: plain markdown notes checked into a public git repository, no paywall or account required to read the source files.

Ideal use cases

• Interview prep: reviewing system design fundamentals before a technical interview, especially if you've already read or are reading the source books and want condensed notes to revisit quickly.
• Quick refresher: looking up how a specific system (e.g., a notification system or a web crawler) is typically decomposed, without re-reading a full chapter.
• Finding further reading: using the linked papers and engineering blog posts as a starting point for deeper research into a subsystem like consistent hashing or distributed message queues.

This is not a good fit if you're looking for runnable code, working implementations, or diagrams and figures reproduced from the books themselves (the notes are text-based summaries, and the project explicitly states it's a work in progress). It's also not a substitute for reading the original books if you need the full explanations, trade-off discussions, and diagrams that the notes are derived from.

Installation

There's no software to install. This is a documentation repository consisting of markdown files organized by chapter. To use it:

git clone https://github.com/liquidslr/system-design-notes.git
cd system-design-notes

Then browse the chapter folders directly, or open the markdown files in any editor or markdown viewer. Alternatively, read the same content on the hosted site:

https://pagefy-blush.vercel.app/system-design/system-design-interview-by-alex-xu

No build step, dependencies, or configuration is required since the repository is purely text content.