07/09/2026 updated
100 % available
CTO | Backend & Data Engineer | AI, SaaS & API Systems
Arao, Japan
Only remote
B.Sc. Computer Science, Tokushima UniversityAbout me
Backend & Data Engineer focused on AI, SaaS, APIs, and automation. I design and build scalable systems from architecture to implementation, and support MoveSave as CTO/Auditor with ledger, antifraud, and audit-ready platform design.
IoTSupabaseApplication Programming Interfaces (APIs)Architecture AnalysisArchitecture FrameworkC Sharp (Programming Language)C++ (Programming Language)Software as a ServiceData IntegrationEmbedded SystemsPython (Programming Language)PostgreSQLMessaging Application Programming InterfaceMySQLNode.js
Backend & API Development
Expertise in building production-grade backend systems and API integrations using Python, Node.js, TypeScript, JavaScript, FastAPI, Django, PHP, Laravel, REST API, and Microservices architectures.
AI, SaaS & Automation
Strong background in AI-powered platforms and automation, including work with OpenAI, Claude, Gemini API, AI Integration, AI Automation, SaaS Development, Workflow Automation, and Recommendation Logic.
Data & Database Engineering
Solid experience in data modeling and database engineering using PostgreSQL, MongoDB, MySQL, Database Design, Ledger Logic, Audit Trail Design, and Transaction Consistency.
Frontend & Full-Stack Development
Proficiency in full-stack development using React, Next.js, HTML, CSS, Dashboard Development, and Responsive Web Apps.
Cloud, DevOps & Tools
Hands-on experience with cloud and DevOps tooling including AWS, Docker, Firebase, Supabase, Git, CI/CD, Unit Testing, and QA.
Business & Payment Systems
Knowledge of business and payment system integration using Stripe, Mercado Pago, Shopify, WordPress, E-commerce, Marketplace Systems, Payment Workflows, and Security Analysis.
Fintech Architecture & Audit
Experience leading technical architecture and economic audits for fintech-style loyalty ecosystems, covering ledger design, antifraud logic, merchant billing, and transaction integrity.
IoT & Embedded Systems
Practical experience with IoT systems using ESP32 and AWS MQTT for device messaging, embedded behavior, and API communication.
Expertise in building production-grade backend systems and API integrations using Python, Node.js, TypeScript, JavaScript, FastAPI, Django, PHP, Laravel, REST API, and Microservices architectures.
AI, SaaS & Automation
Strong background in AI-powered platforms and automation, including work with OpenAI, Claude, Gemini API, AI Integration, AI Automation, SaaS Development, Workflow Automation, and Recommendation Logic.
Data & Database Engineering
Solid experience in data modeling and database engineering using PostgreSQL, MongoDB, MySQL, Database Design, Ledger Logic, Audit Trail Design, and Transaction Consistency.
Frontend & Full-Stack Development
Proficiency in full-stack development using React, Next.js, HTML, CSS, Dashboard Development, and Responsive Web Apps.
Cloud, DevOps & Tools
Hands-on experience with cloud and DevOps tooling including AWS, Docker, Firebase, Supabase, Git, CI/CD, Unit Testing, and QA.
Business & Payment Systems
Knowledge of business and payment system integration using Stripe, Mercado Pago, Shopify, WordPress, E-commerce, Marketplace Systems, Payment Workflows, and Security Analysis.
Fintech Architecture & Audit
Experience leading technical architecture and economic audits for fintech-style loyalty ecosystems, covering ledger design, antifraud logic, merchant billing, and transaction integrity.
IoT & Embedded Systems
Practical experience with IoT systems using ESP32 and AWS MQTT for device messaging, embedded behavior, and API communication.
Experience
Professional experience10+ years
Freelancer since2015
Languages
EnglishFluent
Project history
Lead technical architecture and audit strategy for a fintech-style loyalty ecosystem built on activity tracking, streak logic, merchant participation, and a reward economy. Designed the platform architecture covering ledger-style transaction flows, reward rules, antifraud logic, merchant billing, and auditability. Audited the reward system's economic model across inflation risk, streak incentives, billing flows, balance consistency, and transaction integrity.
Deliver senior engineering support for international clients across AI systems, API integrations, SaaS features, marketplaces, payment flows, and production-ready web applications. Built a graded card marketplace covering registration, shipping integration, reputation and badge logic, antifraud flows, admin dashboard, and disputes. Implemented AI and automation projects including generative content systems, Gemini API prompt interfaces, and recommendation logic. Built backend systems, dashboards, and full-stack applications using React, Next.js, Node.js, Python, TypeScript, PostgreSQL, and MongoDB.
Built and optimized high-performance web applications and API-driven systems for digital content, commerce, and internal business platforms. Reduced website load times through frontend and backend performance optimization, code refactoring, and workflow improvements.