About
Naohiro YozaSystems Engineer
I have worked as a systems engineer for five years. On my own, I also build products end to end, from planning and design to development, launch, and operations. I specialize in turning AI and statistical methods into services people can actually use.
I love basketball.
Owning the whole product
I handle everything myself, from deciding whose problem to solve to design, implementation, testing, launch, and operations. I care about building things that keep running, not just things that ship.
Trust enforced by design
In Himotoku AI, answers cannot be tampered with; in B.PREDICT, predictions cannot be changed after tip-off. Both guarantees live in the database layer. I prefer structural guarantees over "being careful".
Zero running cost
To keep personal products alive for the long run, I aim for zero running cost. I design around free-tier limits with static delivery and in-browser execution.
Turning AI and statistics into products
From a machine learning course to statistical game predictions, I turn AI and statistical methods into real services, designing not only the models but also how they are evaluated and presented.
What I handle in my personal projects
- Planning & requirements
- Design
- Implementation
- Testing
- Launch
- Operations & improvement
Strengths
- Full-stack web development (TypeScript, Next.js, Cloudflare)
- Building AI, machine learning, and statistical models into services
- Architectures that keep running for the long term at little or no cost
Get in touch
I welcome ideas for building products together, collaboration proposals, and feedback on my projects.
Technologies used in my projects
Collected automatically from the tech stacks of the projects on this site.
Frontend
- TypeScript, Used in: Himotoku AI, B.PREDICT, Yubibato
- Next.js, Used in: Himotoku AI, B.PREDICT
- CodeMirror, Used in: Himotoku AI
- GSI tiles, Used in: Koukin Map
- HTML, Used in: Koukin Map
- JavaScript, Used in: Koukin Map
- KaTeX, Used in: Himotoku AI
- Leaflet, Used in: Koukin Map
- MDX, Used in: Himotoku AI
- Pyodide, Used in: Himotoku AI
- Tailwind CSS, Used in: Himotoku AI
Backend & infrastructure
- Cloudflare Workers, Used in: Himotoku AI, B.PREDICT, Koukin Map, Yubibato
- Cloudflare D1, Used in: B.PREDICT, Yubibato
- Hono, Used in: B.PREDICT, Yubibato
- Cloudflare Turnstile, Used in: Himotoku AI
- Resend, Used in: Himotoku AI
- Supabase, Used in: Himotoku AI
Data, AI & machine learning
- Python, Used in: B.PREDICT, Koukin Map
- fontTools, Used in: Koukin Map
- JSON Schema, Used in: Koukin Map
- LightGBM, Used in: B.PREDICT
- openpyxl, Used in: Koukin Map
- pdfminer.six, Used in: Koukin Map
- pypdf, Used in: Koukin Map
- xlrd, Used in: Koukin Map
Testing & operations
- GitHub Actions, Used in: Himotoku AI, B.PREDICT
- Playwright, Used in: Himotoku AI, Yubibato
- Vitest, Used in: Himotoku AI, Yubibato
- axe-core, Used in: Himotoku AI
- PGlite, Used in: Himotoku AI
- Sentry, Used in: Himotoku AI
Other
- Cloudflare Access, Used in: Yubibato
- Cloudflare KV, Used in: Yubibato
- Durable Objects (WebSocket Hibernation), Used in: Yubibato
- Google Forms, Used in: Koukin Map
- React, Used in: Yubibato
- Vite, Used in: Yubibato