John User

I built and deployed Coco English, an AI speaking-practice app now used by students in my English classes. It records spoken responses, evaluates meaning and target-pattern use, and returns pronunciation feedback.

I built the product end-to-end with TypeScript, Next.js, React, Supabase/PostgreSQL, OpenAI, Azure Speech, and Vercel. Its codebase includes 1,300+ automated tests, with Playwright end-to-end coverage and GitHub Actions checks on every push.

I designed dual authentication for teachers and students, phoneme-level pronunciation analysis, content safety for child users, and caching and deterministic paths to reduce paid API costs. I also contributed most of the backend and automated test suite for a Python/Flask university IT support ticketing system.

Alongside teaching English full-time at Sprout English, I completed my Computer Science degree part-time over five years, graduating Summa Cum Laude. Teaching across grade levels helps me build learning tools around real student needs and performance.