Backend / full-stack engineer based in Tokyo, Japan, with around 10 years of experience. Currently at AppBrew; previously at Creatures and HashPort. Led architecture and production operations for ClinCloud's multi-tenant clinical EDC platform.

I design, build, and operate production systems, with experience spanning multi-tenant backends, internal platforms, APIs, and independently built products.

Open to ongoing part-time backend/platform contracting, with fully asynchronous, written-only collaboration through GitHub, Slack, and documentation.

Kotlin/Ktor · TypeScript

Led the architecture, implementation, and production operations of a multi-tenant Electronic Data Capture (EDC) platform supporting clinical workflows for pharmaceutical customers.

• Developed backend and frontend functionality, including tenant isolation and access control.
• Implemented audit trails capturing user attribution, timestamps, and data changes to support traceability in regulated clinical workflows.
• Owned development across the application lifecycle, from design through production maintenance.

Scala/Play · Angular · TypeScript · MySQL · GCP/GKE · Terraform

Developed and maintained an internal information platform for the Pokémon Trading Card Game development team, managing card, product, and illustration data.

• Implemented complex domain-specific business rules, administrative configuration interfaces, and cross-system data synchronization.
• Developed access control and spreadsheet-style data editing workflows.
• Modernized the Angular frontend with Standalone Components, Typed Forms, and JSpreadsheet, delivering the changes to production.

Go/Gin · Next.js · YAML · CEL · Claude · Gemini

Served as the sole engineer on a cross-functional team of approximately four people, also handling technical leadership and project management.

• Designed and implemented a shared, declarative game runtime using YAML and Common Expression Language (CEL).
• Built configuration-driven state transitions, scenario branching, character behavior, and dynamic LLM prompt/context selection.
• Integrated Anthropic Claude and Google Gemini.
• Delivered novel-writing and music-making applications for internal/limited release within approximately two months.

TypeScript · Ethereum · Tezos · Bitcoin · PLT

Developed wallet backend APIs and transaction workflows across multiple blockchain networks, including chain-specific integrations for asset transfers.

Open source (MIT) · Documentation

Developed a cross-platform SDK and setup CLI for capturing, annotating, and submitting visual bug reports directly from mobile applications.

• Supports Expo / React Native, native iOS and Android, and Flutter.
• Distributed through npm, Swift Package Manager, Maven Central, and pub.dev.
• Offers custom submission callbacks or an optional hosted service, KUE Cloud.

Live product · Japanese site

Independently developed and operate a web platform for publishing and discovering fiction, including AI-assisted works.

• Authors can publish stories; readers can discover and read published episodes without an account.
• Supports multilingual publishing and discovery.
• Built with Next.js, TypeScript, Supabase, and LLM integrations.

Languages: TypeScript, Kotlin, Go, Scala, Python, Java
Backend / APIs: Ktor, Play Framework, Gin, Node.js, GraphQL
Frontend: React, Next.js, Angular
Data: MySQL, Redis, Supabase
Cloud & infrastructure: AWS, GCP/GKE, Docker, Terraform
Mobile: Expo / React Native, native iOS / Android, Flutter
Other: YAML/CEL, LLM integrations, blockchain wallet APIs

• GitHub: https://github.com/Ischca
• LinkedIn: https://jp.linkedin.com/in/shota-watanabe-16547a20b