If you are a Junior Engineer (L3/L4), the PDF will likely overwhelm you. Start with Alex Xu or Grokking.
Master the System Design Interview: A Review of Alex Xu’s Insider’s Guide Alex Lu System Design Interview Pdf
Explain why you chose one technology over another. If you are a Junior Engineer (L3/L4), the
: Summarize the design, discuss potential improvements, and address edge cases. Level Up Coding Volume 1: Fundamentals & Classic Problems discuss potential improvements
: Exploring specific components, such as databases, caching, and load balancing.