Alex Xu system design notes free

Gaurav Kumar, the GitHub user behind the handle liquidslr, has published a free set of system-design study notes that tracks all 28 chapters of Alex Xu’s “System Design Interview” series, according to his GitHub repository and companion Pagefy site. Kumar’s GitHub profile identifies him as an AWS engineer in New York and links directly to Pagefy. The notes are organized chapter by chapter and presented as a quick-review resource for candidates preparing for technical interviews. The GitHub repository was last updated about three weeks ago, when the final chapter, “Stock Exchange,” was added. ### Who put the notes together? Gaurav Kumar is listed on GitHub as the operator of the liquidslr account, and his profile describes him as “AWS | CS Grad USC | Interested in ML, Algorithms, Distributed Systems and System Design.” The same profile links to Pagefy, the site hosting the browser-based version of the notes. Kumar has not framed the project as an official Alex Xu product on the pages reviewed. (github.com) GitHub shows Kumar as the latest contributor on the `system-design-notes` repository. The repository description says it contains “Notes of the book System Desgin Interview - An Insider's Guide,” preserving the typo in the original repository text. ### What exactly is free here? Pagefy presents the material as a chapter browser titled “System Design Interview by Alex Xu,” with 28 entries ranging from “Scaling” to “Stock Exchange.” The GitHub repository mirrors that structure in folders named for each chapter. (github.com) Users can read the material without buying a separate course from Pagefy, though the site prompts users to sign in for saved progress and highlights. (github.com) GitHub lists the repository as public, with about 5.6 million? No — 5.6 thousand stars and 1.1 thousand forks at the time of the search results reviewed. Those figures indicate broad reuse among engineers and interview candidates, though GitHub does not break down who starred the project or why. ### How does it line up with Alex Xu’s books? Pagefy’s chapter list matches the 28-chapter sequence associated with Alex Xu’s system-design volumes, including early foundational topics such as rate limiting and consistent hashing and later case studies such as payment systems, digital wallets and stock exchanges. (pagefy.io) ByteByteGo, Xu’s company, continues to market system-design interview training and related technical guides on its own site. (github.com) The GitHub README says the notes were originally based on “System Design Interview books - Vol 1 2nd Ed” and labels the work as “a work in progress.” The repository itself now extends beyond the first 16 chapters listed in that README snapshot, with folders visible for chapters 17 through 28. That expansion appears to have been completed over the past month, based on the repository’s recent commit labels. (pagefy.io) ### What is inside the notes besides summaries? The README includes “Additional Resources” tied to specific chapters, pointing readers to source material on topics such as Amazon Dynamo, Google Bigtable, Discord messaging, Dropbox synchronization and video encoding at Netflix. That structure turns the project into more than a plain outline: it acts as a reading map from interview prompts to underlying engineering papers, blog posts and architecture write-ups. (github.com) Pagefy describes itself as “a free, modern library of system design notes and technical book summaries to help you study faster.” That framing matches the way the Alex Xu notes are presented: short, navigable study material rather than a replacement for the original books. ### Where can candidates find the full set now? (github.com) The full chapter list is live on Pagefy under “System Design Interview by Alex Xu,” and the source files remain public in the `liquidslr/system-design-notes` GitHub repository. GitHub shows the most recent additions — chapters 25 through 28 — were posted within the last three weeks, with “Stock Exchange” listed as the latest chapter. (pagefy.io 1) (pagefy.io 2)