Xu famously includes "Estimation 101." You must calculate:
Based on the methodologies of Alex Xu's System Design Series
Reasons:
⚠️ Note: Unofficial PDFs circulating online often lack diagrams, contain OCR errors, or are outdated (missing Vol 2 content). Many are incomplete.
Define the API explicitly. Don't just say "upload a photo." Say:
POST /v1/users/user_id/images
Body: image_file (binary), caption (string) system design interview alex wu pdf
If you download the PDF, skip to these chapters immediately. These are the most common interview questions:
Yes, absolutely – with caveats.
If you scan any "Alex Wu PDF," you will find a recurring diagram: The high-level design "diamond." It consists of:
Pro tip: Don't just draw the diamond. Explain why the cache sits between the web server and the DB. Xu famously includes "Estimation 101
Covers 16 real-world system design problems with structured solutions, including:
Example problems from Vol 1: