Mobile products, built and supported in production.
React Native engineer focused on practical, high-quality mobile apps.
Six years of end-to-end ownership from architecture to store release.
Based in Nara, working with teams in Osaka and worldwide.
Featured project
Guusto
Employee recognition and rewards used by organizations with frontline teams.
- Outcome
- Highest-rated recognition platform on G2
- Responsibility
- Sole React Native developer; architecture, delivery, releases, and support
- Platforms
- iOS and Android
- Time
- Six years
Featured project · My own product
KiraKiran
Online booking, client records and payments for solo salons in Japan: nail, eyelash, hair and esthetic.
- Stage
- Live on the App Store and the web
- Responsibility
- Everything: design, app, backend, payments, release and support
- Stack
- React Native, Expo, TypeScript, Supabase
- Integrations
- Stripe, Square, Tap to Pay on iPhone, LINE
Mobile QA with Maestro
Reliable staging coverage for KiraKiran's real iOS flows.
Built a staging-locked Maestro and YAML black-box harness covering smoke, adversarial, CRUD, restart, public-booking, and Stripe card PaymentSheet flows. Added stable selectors, safety guards, JUnit reports, screenshots, cleanup, and device targeting. Cross-role messaging was designed and instrumented as a coordinated two-device protocol.
Recommendations
From Guusto engineering leadership
“I had the pleasure of supervising Ciaran, where he owned the maintenance and evolution of our React Native mobile app. He is one of the most dedicated and hardworking engineers I've worked with. He handled production issues quickly and calmly, delivered releases reliably, and always brought creative solutions to the table. As his scope grew, he also supported the broader React Native team and led a thorough handover.”
“He demonstrated strong technical independence, handling feature development, releases, production issues, and the day-to-day challenges of maintaining a mobile application in production.”
Production ownership
I joined Guusto when the company had seven employees. Before a product team was hired, I often decided what needed attention next. Later I worked from Figma designs and Jira tickets with product, design, backend, and web teams.
Built and shipped
- Designed the React Native and TypeScript app architecture and built the mobile app from scratch.
- Integrated REST and GraphQL-backed data, native services, push notifications, authentication, wallets, and recognition flows.
- Handled certificates, store submissions, review rejections, version upgrades, performance work, and production incidents.
Worked with people
- Reviewed designs throughout six years at Guusto and reviewed teammates' code during the final six months.
- Debugged mobile problems with React Native, backend, and web engineers across time zones.
- Documented the app and trained the successor team during a three-month technical handover.
Building KiraKiran
I started KiraKiran in July 2026 after seeing how a solo nail salon runs on LINE chats, Instagram DMs and memory. I design, build, ship and support all of it myself.
Built and shipped
- One React Native, Expo and TypeScript codebase for the iPhone app and the web version, with Japanese and English.
- Supabase backend: authentication, database migrations with row-level security, and edge functions.
- EAS builds, App Store releases and over-the-air updates.
Payments and messaging
- Deposits and prepayment through the salon's own Stripe or Square account, and Tap to Pay on iPhone in the salon.
- LINE integration, so salons send booking messages from their own LINE official account.
- Shaped through regular feedback from an independent nail technician using it for day-to-day salon work.
Experience
Mobile product work is the centre of my experience, supported by earlier web and game development.
KiraKiran
Founder and sole engineer
Booking, client-records and payments app for solo salons in Japan, live on the App Store and the web. Design, React Native app, Supabase backend, payments, releases and support.
Guusto Gifts Inc.
Frontend Engineer, contract and remote
Sole React Native developer for the production iOS and Android app. Owned architecture, feature delivery, releases, incident response, performance work, reviews, and final technical handover.
Independent game development
Unity and C# developer
Built strategy, simulation, puzzle, RPG, and action prototypes for mobile, web, and desktop.
Education
- RED AcademyFull Stack Development bootcamp
- British Columbia Institute of TechnologyGame Development coursework
- British Columbia Institute of TechnologyComputer Information Technology
Skills
My strongest skills come from building, releasing, and supporting mobile apps.
Mobile product engineering
- React Native
- Expo
- TypeScript
- JavaScript
- React
- Responsive mobile UI
- Accessibility and testID selectors
Production ownership
- iOS and Android releases
- App Store and Google Play review
- Native integrations
- Push notifications
- Deep links
- Performance and crash triage
- On-call incident response
Quality and testing
- Maestro
- YAML
- Mobile end-to-end testing
- Black-box and adversarial testing
- Regression and smoke testing
- JUnit reporting
- Synthetic test data
- Release QA
Platform and collaboration
- REST
- GraphQL
- Node.js tooling
- Supabase
- Git and Bitbucket
- Docker locally
- Jira
- Code and design reviews
- Cross-team debugging
What colleagues say
“He played a foundational role in building the mobile app from the ground up, and his contributions have shaped the product in a lasting way.”
“He's not only a talented mobile engineer but also someone who's incredibly communicative, thoughtful, and easy to work with.”
Contact
I am looking for React Native and mobile product roles in Osaka, elsewhere in Japan, or remote.