ByteByteGo

About ByteByteGo

ByteByteGo is a newsletter that explains complex system design concepts in simple terms, created by the authors of the bestselling System Design Interview book series . Founded by Alex Xu and co-founder Sahn Lam approximately two years before August 2024, the newsletter was driven by their passion for system design and desire to educate engineers . Xu, a software engineer and Carnegie Mellon University alumnus, publishes the newsletter twice weekly with a deep dive on Thursdays and system design fundamentals on Saturdays. The newsletter covers topics including distributed systems, database architecture, API design, cloud computing, and software engineering best practices through visual diagrams and clear explanations.

The newsletter reached 1 million subscribers in August 2024, achieving this milestone in just over two years . As of 2025, ByteByteGo has over 1 million subscribers , making it one of the largest technical newsletters in the software engineering space. The newsletter operates on a freemium model with free and paid subscription tiers, with paid subscribers receiving access to an extensive archive and additional content. ByteByteGo has expanded beyond the newsletter to include a companion website offering text-based courses, system design interview preparation materials, and visual learning resources for engineers preparing for technical interviews or deepening their system design knowledge.