Metavuild
Metavuild
A metaverse housing showroom.
A Unity-based metaverse housing-showroom service I built as Co-founder / CTO at ARKLET (now FriSti) — owning everything from the web frontend to the experience design.
UnityC#MetaverseWeb
Software Engineer / Creator
sa-san
Make the dots.
You can't connect the dots looking forward; you can only connect them looking backward. So first, give your all to the thing in front of you — and make the dots.
Software engineer at Mercari, working from the frontend out to full-stack. Games, a startup, research. Trusting the dots will connect one day, I keep making new ones — today included.
Things I have built
Works
moji-sand
A once-a-day word-play app.
A sandwich of words you can play once a day — a personal project with simple rules and a cute UI. Live on the App Store (Google Play under review).
React NativeTypeScriptGame
Download on theApp StoreGET IT ONGoogle Play
MagPoint
Coming soonA magnetic cursor for the web.
A pointing-assist & accessibility extension that pulls your cursor toward the nearest clickable element — bubble-cursor HCI research, brought to the open web as OSS. Chrome Web Store release in progress.
TypeScriptChrome ExtensionHCIOSS
yumetate
Design your dream home with generative AI.
A home-building service where you chat about your ideal home and generative AI proposes the design. Built at FriSti (formerly ARKLET).
Generative AIWeb
typed-notion-cli
Type-safe TS schemas from Notion.
A CLI that generates type-safe TypeScript schemas from Notion data sources.
TypeScriptCLINotion
cortex
A personal tool, built in Go.
A small Go tool to smooth out my daily workflow.
GoCLI
dotgo
Declarative dotfiles in Go.
A Go CLI for managing dotfiles declaratively.
GoCLI
Things I have written
Writing
- [Urgent] On the Next.js (CVE-2025-66478) / React (CVE-2025-55182) vulnerabilitiesZenn♥ 204 likes
- Building a CLI to offload Claude Code's AI memos into NotionZenn♥ 17 likes
- I stopped repeating the same prompt — a self-healing 'recurrence-prevention loop' for SkillsZenn♥ 2 likes
- Testing Next.js (Edge Runtime) Route Handlers: where I got stuck and how I solved itZenn♥ 3 likes
Background
Experience
Now
Software Engineer
Mercari
Joined as a frontend engineer in the Customer Service domain; now working full-stack across the area.
2022 – 2025
Co-founder / CTO
ARKLET (later FriSti)
Built the metaverse housing showroom Metavuild in Unity, and worked on the generative-AI home-building service Yumetate. Led engineering end to end — from the web frontend to standing up an agile process.
2024
Software Engineer Intern
Mercari / Rakuten / CyberAgent
React/PHP/Go at Mercari, Next.js/FastAPI at Rakuten, and won the overall MVP at CyberAgent's game-development hackathon.
2020 – 2026
M.Sc. in Information Systems
Nagoya University
Studied electrical/electronic/information engineering as an undergrad, then completed the master's program in Information Systems. Thesis: object detection with vehicle-infrastructure (V2I) cooperation — awarded the IPSJ SIG Embedded Systems Excellent Presentation Award at ETNET2026.
Tools of the trade
Skills
Languages
- TypeScript
- Go
- C#
- PHP
Frameworks
- React
- Next.js
- React Native
- Unity
- FastAPI
Beyond code
Activities
Life is Tech! Mentor (2022 – 2025)
Taught Unity to teenagers and trained university student-mentors (Leaders).
Nagoya University Symphony Orchestra
Playing violin in the student orchestra.
Contact
Contact
Work inquiries, thoughts, anything — feel free to reach out.
support@sa-san.com