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Takeshi Juan

Game Tools · QA Automation · Build Infrastructure

Takeshi Juan

Building reliable game development environments through engine integration, QA automation, CI/CD, and production-focused tooling.

Tokyo, Japan

About

I craft software that bridges technical excellence with exceptional user experience—from AAA game engines to production-grade AI systems.

After graduating from a university in Taiwan in 2017, I began my career at X-LEGEND Entertainment developing smartphone MMORPGs. I then completed my Master's in Information Science and Engineering at Tokyo Institute of Technology.

At Marvelous, I developed the arcade rhythm game "WACCA" using Unreal Engine 4, focusing on game UI implementation and server communication systems.

My time at Square Enix involved building internal QA automation systems for major titles including FF7 Rebirth and Dragon Quest series, integrating with UE4/5 and Python backend systems.

Currently at Kyuzan, I lead a 6-member client engineering team for a new NFT mobile game, driving technical decisions from architecture design to CI/CD pipeline construction.

Clean Architecture

Domain-driven design with clear separation of concerns for maintainable, scalable codebases.

AI-Augmented Development

Leveraging Claude Code, Warp, and Windsurf to maximize team output and code quality.

Craftsmanship

Obsessive attention to detail, from pixel-perfect UI to optimized system performance.

Skills

50+

Technologies

Languages

12
C#C++CPythonTypeScriptJavaScriptPHPSwiftObjective-CHTML/CSSBashPowerShell

Game Engines

3
UnityUnreal Engine 4/5CRYENGINE

Frontend & Frameworks

6
Next.jsReactTailwind CSSReact Hook FormZodjQuery

Backend & Frameworks

5
NestJSNode.jsVercel AI SDKZend FrameworkLaravel

Cloud & Infrastructure

8
AWSGoogle Cloud PlatformVercelSupabaseFirebaseDockerGitHub ActionsFastlane

Databases

3
PostgreSQLMySQLRedis

Payments & APIs

4
StripePayPayResendBoatraceOpenAPI

Testing

3
PlaywrightVitestJest

AI & Productivity

6
OpenAI GPT-4Vercel AI GatewayClaude CodeWarpWindsurfFigma

Experience

2025

Hengen Studio

Side Project
Tokyo, Japan

Founder & Full-Stack Engineer

Modern image transformation service using Generative AI APIs. Visual intelligence and production-grade AI integration.

2025

SUIJIN AI

Side Project
Tokyo, Japan

Founder & Full-Stack Engineer

AI-powered boat-race prediction and analysis platform. Next.js 16, Supabase, Vercel AI SDK, PayPay integration.

2024 – Present

Kyuzan Inc.

Tokyo, Japan

Client Engineering Lead

Leading 6-engineer Unity client team. Established Clean Architecture, GitHub Actions / Fastlane CI/CD pipeline (-70% deploy time), shared dev infrastructure across the team.

2022 – 2024

Square Enix

Tokyo, Japan

QA Automation / Tools Engineer

Built internal QA automation framework for AAA titles (FF7 Rebirth, Dragon Quest). UE4/5 plugin integration, Python orchestration backend, editor tooling for non-engineer QA staff.

2020 – 2022

Marvelous Inc.

Tokyo, Japan

Game Engineer

WACCA arcade rhythm game. UE4/C++ development, UI systems, server communication.

2019 – 2022

Ielove Group

Tokyo, Japan

Web Engineer

Real estate web platform. Full-stack PHP development, internal library design.

Part-time during graduate studies

2018 – 2020

Tokyo Institute of Technology

Tokyo, Japan

Master's Student

Information Science and Engineering. Advanced research in computer science.

2017 – 2018

X-LEGEND Entertainment

Taiwan

Game Engineer

Aura Kingdom mobile MMORPG. CRYENGINE/C++ development, gameplay systems.

© 2026 Takeshi Juan

Crafted with precision in Tokyo