Paul Nguyen

Paul Nguyen

Applied AI Engineer — Safety-Critical AI Products | Building Autodidact (local-first agent that learns) | PhD (Adversarial ML & Security)

Blog posts

2026

A transformer block from scratch: demystifying LLMs by building one

13 minute read

Published:

Many people see LLMs as a magic black box. At the architecture level, they’re simpler than they look. The core of every modern LLM - GPT, Claude, Gemini, Llama - is a transformer block. Stack one transformer block N times (typically 12 to 80), add an embedding layer at the input and an output head at the output, and you have a working ChatGPT-style LLM. That’s the whole recipe.

Stop Training Your LLM Router: Zero-Shot Confidence Beats Supervised Baselines

5 minute read

Published:

TL;DR: We tested whether you actually need labeled training data to route queries between a cheap local LLM and an expensive cloud model. You don’t. Average token log-probability — available for free from the first query — matches supervised routing in-distribution and crushes it when the query distribution shifts. We tested across 3 model families, 2 datasets, ~4,500 queries, and $123 in cloud costs. All code and data are open.

2025

What Automotive AI Taught Me About Responsible Deployment

9 minute read

Published:

When you ship AI into a vehicle, the consequences of failure aren’t abstract. They’re not a bad user review or a dip in engagement metrics. They’re a driver who takes their eyes off the road because the system said something confidently wrong, or a voice assistant that crashes mid-navigation and leaves someone lost on an unfamiliar highway. Shipping AI where failures have physical consequences changes how you think about deployment — permanently.

2024

AI Agents: Buzzword or Paradigm Shift?

less than 1 minute read

Published:

“AI agent”—a fancy buzzword for AI model integration, or is there more to it? With increasing autonomy and decision-making capabilities, are we just rebranding models, or is this a true paradigm shift?

2020

Best Student Paper Award at HOST 2020

less than 1 minute read

Published:

I’m excited to share that our paper “A Novel Golden-Chip-Free Clustering Technique Using Backscattering Side Channel for Hardware Trojan Detection” won the Best Student Paper Award at the 2020 IEEE International Symposium on Hardware Oriented Security and Trust (HOST).