About

Hi, I’m Billy, an Applied Scientist at Amazon, based in Japan. My work sits between science and engineering: building ML and AI systems and shipping them to production, not just prototyping in a notebook.

The stack I work across:

• Causal inference: treatment effects, heterogeneity (CATE), overlap and sensitivity diagnostics.
• ML in production: modeling, evaluation, and the pipeline/MLOps work that keeps it alive after launch.
• Optimization and decision systems: turning model outputs into something someone can act on.
• GenAI and LLM systems: agentic tooling, multi-agent workflows, and eval frameworks.

This site is where I archive what I’m learning, equal parts public notebook and reference for my future self.

Reach out

If something here is useful, wrong, or worth a conversation, I’d rather be corrected than left with a mistake on the internet. Email: bilguunbatsaikhan88@gmail.com