You can find many deep-dives into specific chapters (like Proximity Service or Wallet Design) for free on the ByteByteGo Newsletter . system-design-interview-an-insiders-guide-volume-2.pdf
Volume 1 covered the basics: Designing YouTube, Google Drive, and Uber. Volume 2, however, takes the gloves off. It focuses on and newer architecture patterns . You can find many deep-dives into specific chapters
Here are some frequently asked questions about the System Design Interview Volume 2 PDF: and Uber. Volume 2