LLM System InterviewHao Hoang · First edition, 2026Home

About the Author

I am Hao Hoang, an applied AI/ML engineer and technical writer. I am based in Los Angeles, California, and I am originally from Quang Tri, Viet Nam.

I own AI Interview Prep and write for the community every day on Substack and on LinkedIn. On Substack I publish Daily AI Interview Questions and longer notes on LLM system design, reinforcement learning, vision-language models, RAG-style retrieval, and other high-signal topics for engineers and researchers preparing for rigorous AI interviews. On LinkedIn I share the same thread of ideas in shorter, daily posts so people can follow along between editions. That public writing reaches more than 55,000 LinkedIn followers and 12,000 Substack readers, and it is the main place I teach, learn in public, and answer what the community is asking about.

About this book. I am the sole author: I researched and wrote every chapter myself, without co-authors or ghostwriters. I wrote it because I wanted a single, opinionated reference for the patterns I kept having to re-derive when preparing for interviews and when shipping LLM systems in production-at the intersection of research, systems engineering, and deployment.

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