Hire the Best Kotlin Developers
in Japan

👋 Hello and welcome! I’m a passionate Senior Full-Stack Developer with 9+ years of experience, specializing in modern frontend & backend frameworks, AI, Web Scraping, Web3, and Mobile App Development. I don’t just write code—I craft high-performance, scalable, and future-ready solutions tailored to your unique needs. Whether you're a startup looking to disrupt the market or an established business aiming for digital transformation, I'm here to bring your vision to life. What I Can Do for You: ✅ Frontend Excellence: React.js, Next.js, Vue.js, Svelte, Angular, TypeScript, Tailwind CSS, Material-UI ✅ Backend Mastery: Node.js (Express/Nest.js), Python (Django/Flask), Laravel, Java Spring, .NET ✅ AI & Web3 Solutions: ChatGPT/OpenAI, TensorFlow, Blockchain, Smart Contracts, Solidity, NFT Platforms ✅ Web Scraping & Automation: Puppeteer, Selenium, Scrapy, BeautifulSoup, Reverse Engineering, Captcha Bypass ✅ Mobile App Development: React Native, Flutter, Swift, Kotlin, Expo – delivering seamless cross-platform experiences ✅ Database & API Integration: MySQL, PostgreSQL, MongoDB, Redis, Firebase, REST, GraphQL, Stripe, Twilio, Google Maps ✅ DevOps & Cloud: AWS, GCP, Docker, Kubernetes, CI/CD Pipelines Why Clients Love Working With Me: - 100% Client Satisfaction – I treat every project as my own and strive for perfection. - Fast & Reliable – Clear communication, quick execution, and on-time delivery. - Scalable & Secure Code – Best practices for performance optimization & cybersecurity. - Innovative Problem-Solver – I don’t just build software; I create solutions that drive success. - Long-Term Collaboration – I aim to build lasting relationships with my clients. Let’s build something amazing together! Message me now and let’s discuss how I can help you achieve your goals.

I build reliable backend systems, AI-enabled applications, and speech-processing pipelines using Python, FastAPI, SQL, AWS, and Docker. With over six years of professional software development experience, I can support a project from requirements and API design through implementation, testing, deployment, and maintenance. I can help you with: • Python and FastAPI backend development • REST API design, integration, and documentation • AI/ML service integration and data-processing pipelines • Speech AI systems, including ASR, TTS, and PyTorch-based workflows • Relational and time-series database design • AWS S3, Docker, Linux, Git, and deployment workflows • Integration with React, Next.js, Flutter, Kotlin, and mobile applications • Debugging, maintenance, and improvement of existing systems My professional experience includes: • Healthcare platforms for clinical video uploads, AI analysis, result management, and processing histories • A hospital-facing sleep-monitoring data management system • Healthcare mobile applications using Flutter, Health Connect, HealthKit, Unity, and iOS • A LINE bot supporting content submission, online payments, and administration • Speech-recognition and text-to-speech research involving Japanese-accented English and aviation communication I am currently pursuing a Ph.D. in Computer Science and Engineering at the University of Aizu. I have experience working with multinational teams and communicating with both technical and non-technical stakeholders in English, Japanese, and Mandarin Chinese. If you need a dependable engineer to build a new backend, integrate an AI service, or improve an existing application, feel free to send me a message.

I am a Quadlingual who speaks Japanese Thai and English at native-like fluency and I offer services in Japan, Thailand, and the US for anyone seeking assistance in language, and consultation services for those countries. I am a full stack developer with strong experience in Javascript and Python and tailor SaaS services for you

If you are looking for a skilled Android Developer, you are at the right place! I have a solid background in creating complex mobile applications. I can work independently and respect a deadline. Let's hop in a quick message!

Senior Fullstack Engineer with 8+ years of experience, based in Tokyo. I build web and AI products end-to-end — from idea and architecture to a fast, polished product your users love. Right now I'm not only building for clients: I'm also shipping my own consumer AI products (an AI companion app and an anime-tracking app). So I know firsthand how to take a product from zero to real users — not just deliver code. WHAT I DO FOR YOU: - End-to-end product development (MVP → scale): architecture, UI/UX, frontend, backend, cloud. - AI integrations: LLM features, OpenAI Vision / image parsing, automation, recommendations. - Performance & accessibility: optimized for speed (perfect Lighthouse scores) and great UX. - Cost-optimized, scalable AWS architecture: low maintenance cost while scaling to many users. I've built 30+ web applications from scratch (MVPs) across my career, so I've likely already built whatever you need: - Dashboards with charts and data tables · REST APIs · Landing pages - Native apps (Android, iOS, desktop) · Payments (Stripe) - ETL pipelines & web crawlers · Auth / authorization - Real-time (WebSockets), chat, video · Email notifications · Logging & error monitoring TECH I WORK WITH: - Languages: TypeScript / JavaScript, Python, Node.js, Shell - Frontend: React, Next.js, Remix, Tailwind - Backend: Nest.js, Express, Prisma, Drizzle - AI: OpenAI API (LLM + Vision), AI product development - Databases: PostgreSQL, MySQL, SQLite, MongoDB, Redis, DynamoDB - AWS: Lambda, API Gateway, EC2, ECS, RDS, S3, Route53, CloudWatch, Serverless - DevOps: CloudFormation, SAM, CI/CD (GitHub Actions, CodePipeline), Docker CREDENTIALS: - AWS Certified Solutions Architect – Associate · 100% Job Success · based in Tokyo (JLPT N1). WHY WORK WITH ME: - Proactive: I suggest effective solutions without eating up your time. - Fast: chances are I've solved your problem before. - Responsive: replies in under 24 hours. - Quality-obsessed: your solution should work perfectly. Not sure yet if I'm the right fit? Contact me for a free 30-minute consultation — no strings attached.

𝐒𝐭𝐫𝐮𝐠𝐠𝐥𝐢𝐧𝐠 𝐰𝐢𝐭𝐡 𝐬𝐥𝐨𝐰, 𝐜𝐥𝐮𝐧𝐤𝐲 𝐚𝐩𝐩𝐬 𝐨𝐫 𝐦𝐢𝐬𝐬𝐞𝐝 𝐥𝐚𝐮𝐧𝐜𝐡 𝐝𝐞𝐚𝐝𝐥𝐢𝐧𝐞𝐬 ? I build fast, scalable Flutter and React Native apps powered by AI designed to solve real business problems and accelerate growth. If you need a mobile app that looks polished, works flawlessly, and drives real impact I deliver. With 𝐨𝐯𝐞𝐫 10 𝐲𝐞𝐚𝐫𝐬 of development experience, I specialize in high-performance cross-platform apps that combine clean architecture, intuitive UI, and 𝐀𝐈 𝐚𝐮𝐭𝐨𝐦𝐚𝐭𝐢𝐨𝐧 to help startups and enterprises scale smarter and faster. 𝐈 𝐬𝐨𝐥𝐯𝐞 𝐜𝐨𝐦𝐦𝐨𝐧 𝐩𝐚𝐢𝐧 𝐩𝐨𝐢𝐧𝐭𝐬 𝐥𝐢𝐤𝐞: Laggy or crash-prone apps across devices Complex backend or third-party API integration Low conversions from unclear user journeys Secure auth flows, GDPR/HIPAA compliance Real-time analytics, automation & notifications Frictionless deployment to Play Store, App Store & Firebase 𝐓𝐞𝐜𝐡 𝐒𝐭𝐚𝐜𝐤 𝐎𝐯𝐞𝐫𝐯𝐢𝐞𝐰 : 𝐅𝐫𝐨𝐧𝐭𝐞𝐧𝐝: Flutter, React Native, Swift, Kotlin, Java, JavaScript, TypeScript 𝐁𝐚𝐜𝐤𝐞𝐧𝐝: Node.js, NestJS, Express, Laravel, Firebase, PHP 𝐃𝐚𝐭𝐚𝐛𝐚𝐬𝐞𝐬: PostgreSQL, MySQL, MongoDB, Firestore, DynamoDB 𝐈𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐢𝐨𝐧𝐬: Stripe, PayPal, Twilio, Facebook, Google APIs, AWS, Docker 𝐒𝐩𝐞𝐜𝐢𝐚𝐥 𝐅𝐞𝐚𝐭𝐮𝐫𝐞𝐬: Push Notifications, OAuth, WebSockets, Chat, Video Calls (Twilio) 𝐀𝐩𝐩 𝐓𝐲𝐩𝐞𝐬 𝐈 𝐁𝐮𝐢𝐥𝐝 : AI-powered chatbots, voice bots, and automation tools On-demand services: telemedicine, delivery, repairs Multivendor eCommerce and retail platforms Appointment scheduling and booking systems Cryptocurrency wallets and fintech apps IPTV, OTT, and media streaming applications SaaS and marketplace mobile platforms (𝐁𝐞𝐟𝐨𝐫𝐞 𝐖𝐞 𝐒𝐭𝐚𝐫𝐭, 𝐘𝐨𝐮 𝐆𝐞𝐭:) A free strategy call Detailed technical documentation Transparent pricing and clear timeliness 𝐇𝐨𝐰 𝐈 𝐂𝐚𝐧 𝐇𝐞𝐥𝐩 : Full-cycle app development from idea to launch Optimize or refactor your existing mobile app Integrate AI/LLMs like GPT into your workflow Long-term support, updates & publishing assistance If you're launching a startup, modernizing your app, or scaling your mobile presence let’s build something users trust and love. 📩 Message me to discuss your app or 𝐬𝐜𝐡𝐞𝐝𝐮𝐥𝐞 𝐚 𝐟𝐫𝐞𝐞 𝐜𝐨𝐧𝐬𝐮𝐥𝐭𝐚𝐭𝐢𝐨𝐧.