07/28/2026 updated
100 % available
Senior Fullstack & AI Engineer
Yokohama, Japan
Only remote
Bachelor's Degree of Computer ScienceAbout me
Iām a Full-Stack AI Developer with 9+ years of experience building modern, scalable, and user-friendly applications. My focus is combining AI (LLMs, RAG pipelines) with robust frontend and backend development to deliver end-to-end solutions.
RAGGitHub ActionsLLMOpenAIGeminiLlamaIndexAzure DevOpsOllamaFlutterASP.NETJava (Programming Language)JavaScript.NET FrameworkArtificial IntelligenceArchitecture
I am a Senior Full Stack Software and AI Engineer with over 10 years of experience delivering scalable, secure, and high-performance applications for startups and enterprise clients. My expertise spans frontend, backend, cloud infrastructure, DevOps, artificial intelligence, and blockchain development.
Frontend: React, Next.js, Vue.js, Angular, TypeScript, JavaScript, HTML5, CSS3, Tailwind CSS, Material UI, Redux, React Query, Zustand.
Backend: Node.js, Express.js, NestJS, FastAPI, Django, Flask, ASP.NET Core, Spring Boot, Ruby on Rails, Laravel, PHP, Java, Go, GraphQL, REST APIs, gRPC, Microservices.
Artificial Intelligence: OpenAI, Claude, Google Gemini, Azure OpenAI, LangChain, LangGraph, LlamaIndex, Model Context Protocol (MCP), AI Agents, Retrieval-Augmented Generation (RAG), Prompt Engineering, Semantic Search, Vector Databases, Ollama.
Databases: PostgreSQL, MySQL, SQL Server, Oracle, MongoDB, Redis, Firebase, Elasticsearch, Pinecone.
Cloud & DevOps: AWS, Microsoft Azure, Google Cloud Platform, Docker, Kubernetes, Terraform, GitHub Actions, Jenkins, CI/CD, Nginx, Apache.
Blockchain: Solidity, Ethereum, EVM, Web3.js, Ethers.js, WalletConnect, Wagmi, dApps, DeFi, NFT platforms.
I have extensive experience designing system architecture, developing scalable APIs, integrating AI into existing products, building cloud-native applications, optimizing application performance, and leading projects from concept to production.
I also mentor engineers through code reviews, architecture discussions, and best practices while collaborating effectively with distributed teams to deliver reliable, maintainable, and business-focused software solutions.
Experience
Professional experience10+ years
Freelancer since2026
Languages
EnglishFluent
Project history
ć»Led the architecture and development of enterprise-grade AI applications using Node.js, Python, and Go, building scalable intelligent automation solutions and AI-powered web applications with React, Next.js, and TypeScript.
ć»Designed and implemented production-ready AI agents using OpenAI, Claude, Google Gemini, LangChain, LangGraph, and Model Context Protocol (MCP), while developing high-performance RAG systems with vector databases, semantic search, and document indexing.
ć»Developed scalable backend services and RESTful APIs with Node.js, FastAPI, and Go, orchestrating LLM workflows, AI inference pipelines, authentication, asynchronous processing, and real-time streaming capabilities.
ć»Deployed cloud-native AI platforms on AWS using Docker, Kubernetes, Terraform, GitHub Actions, and CI/CD, ensuring high availability, security, scalability, and reliable production deployments.
ć»Mentored junior and mid-level engineers through code reviews, architecture discussions, and technical guidance, collaborating closely with cross-functional teams to establish engineering best practices and successfully deliver production-ready AI solutions.
ć»Led a team of developers in designing and delivering scalable full-stack web applications using Node.js, Ruby on Rails, C# (.NET Core), React, Next.js, and TypeScript, providing technical leadership, code reviews, sprint planning, and architectural guidance.
ć»Developed decentralized applications (dApps) on the Ethereum blockchain, building Solidity smart contracts and integrating Web3.js, Ethers.js, WalletConnect, and Wagmi to deliver secure blockchain-based user experiences.
ć»Designed and implemented high-performance RESTful and GraphQL APIs with Node.js, Ruby on Rails, and ASP.NET Core, supporting real-time features, high-volume transaction processing, and scalable enterprise platforms.
ć»Engineered blockchain solutions including payment platforms, NFT marketplaces, and DeFi applications, implementing secure smart contract interactions, on-chain/off-chain synchronization, and optimized database architectures with PostgreSQL, MySQL, MongoDB, and Redis.
ć»Established modern development workflows by implementing Docker, AWS, GitHub Actions, Jenkins, and CI/CD pipelines, while mentoring junior engineers and promoting software engineering best practices to improve code quality and delivery efficiency.
ć»Developed and maintained full-stack SaaS and enterprise web applications using Node.js, PHP, Java, MySQL, JavaScript, HTML5, and CSS3, delivering scalable solutions for business process automation and customer management.
ć»Built responsive, user-centric frontend applications using JavaScript, HTML5, CSS3, Bootstrap, and jQuery, creating reusable UI components and ensuring cross-browser compatibility, performance, and accessibility.
ć»Designed and integrated RESTful APIs with frontend applications using Node.js, PHP, and Java, implementing authentication, data synchronization, reporting, and third-party service integrations to support business workflows.
ć»Collaborated closely with UI/UX designers, QA engineers, product managers, and backend developers throughout the Agile development lifecycle, translating business requirements into high-quality, maintainable software solutions.
ć»Optimized application performance through frontend enhancements, efficient API communication, and MySQL database tuning, while participating in system design, testing, deployment, and ongoing maintenance of SaaS platforms.