Yun-Chung (Eric) Liu

• Python
• TypeScript
• JSON Schema
• Manim
• FFmpeg
• Docker
• AWS Polly
• Cartopy
• Pillow
• MediaWiki API

It turns a plain-language topic into a narrated lesson video: animated math, graphs, and diagrams with synchronized captions. It is built to be deterministic, so the same input always produces the same video. One JSON Schema generates both the Python and TypeScript types, the layout engine rejects content that won’t fit before rendering, and the renderer runs in Docker with networking off.

History lessons bring in real sources. Cartopy draws region maps from Natural Earth data, with borders at a given date from the historical-basemaps dataset. Paintings, portraits, and photos come from Wikimedia Commons, the Met, and the Library of Congress, each checked for its licence and credited on screen. Dates and names come from Wikipedia through the MediaWiki API instead of the model’s memory.

A three-minute lesson costs about eight cents, nearly all of it text-to-speech. Generative video models run $18 to $135 for the same length, and none of them can render a correct equation.

Math · 2:31 The derivative of x³ History · 2:56 From Republic to Empire: How Rome Changed

• Python
• RAG
• Chroma
• BM25
• LLM APIs
• pytest

Ask a plain-English question about any US public company and get an answer built only from its SEC filings. It pulls filings from EDGAR on demand and retrieves with a hand-rolled mix of BM25 and vector search, no RAG framework underneath. Every quote is checked against the source before it’s shown, and if the filings don’t cover the question it says “not disclosed” instead of guessing. The eval set I built alongside it is what caught my abstention thresholds failing to generalize across companies.

• Android
• Java
• TensorFlow Lite
• Speech-to-text

An Android app that turns a spoken movie review into a rating. It uses Google Assistant Service to transcribe what you say, then runs a TensorFlow Lite sentiment model on the phone to score it. The point was that the rating should come from your actual words, not a star you tap without thinking about it.

move your mouse

• Unity
• C#
• Game design

A small arcade game built in Unity and C#, start to finish. I led the team of four, ran the design calls, and put together the obstacle dodging, power-ups, and scoring.

Run Bear Run! Team of 4 · WashU Bear Run Play on itch.io