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Hi, I’m Yamamoto Akio, a Senior Frontend Engineer based in Osaka with 8+ years building scalable, data-driven web apps. I specialize in React, TypeScript, and modern JavaScript, delivering real-time dashboards and interactive UIs that empower users to explore complex data. I’m also comfortable on the backend, having worked with Node.js, Golang, and .NET, and I enjoy bridging the gap between design, engineering, and product to create cohesive experiences. I’m passionate about mentoring junior developers, contributing to design systems, and improving development efficiency through robust CI/CD, performance optimizations, and thoughtful architecture. I thrive in collaborative environments and love turning challenging business problems into scalable solutions.…Hi, I’m Yamamoto Akio, a Senior Frontend Engineer based in Osaka with 8+ years building scalable, data-driven web apps. I specialize in React, TypeScript, and modern JavaScript, delivering real-time dashboards and interactive UIs that empower users to explore complex data. I’m also comfortable on the backend, having worked with Node.js, Golang, and .NET, and I enjoy bridging the gap between design, engineering, and product to create cohesive experiences. I’m passionate about mentoring junior developers, contributing to design systems, and improving development efficiency through robust CI/CD, performance optimizations, and thoughtful architecture. I thrive in collaborative environments and love turning challenging business problems into scalable solutions.

Yamamoto Akio

Front-End Developer, Full Stack Developer, Web Developer, +3

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Hi, I’m Yamamoto Akio, a Senior Frontend Engineer based in Osaka with 8+ years building scalable, data-driven web apps. I specialize in React, TypeScript, and modern JavaScript, delivering real-time dashboards and interactive UIs that empower users to explore complex data. I’m also comfortable on the backend, having worked with Node.js, Golang, and .NET, and I enjoy bridging the gap between design, engineering, and product to create cohesive experiences. I’m passionate about mentoring junior developers, contributing to design systems, and improving development efficiency through robust CI/CD, performance optimizations, and thoughtful architecture. I thrive in collaborative environments and love turning challenging business problems into scalable solutions.…Hi, I’m Yamamoto Akio, a Senior Frontend Engineer based in Osaka with 8+ years building scalable, data-driven web apps. I specialize in React, TypeScript, and modern JavaScript, delivering real-time dashboards and interactive UIs that empower users to explore complex data. I’m also comfortable on the backend, having worked with Node.js, Golang, and .NET, and I enjoy bridging the gap between design, engineering, and product to create cohesive experiences. I’m passionate about mentoring junior developers, contributing to design systems, and improving development efficiency through robust CI/CD, performance optimizations, and thoughtful architecture. I thrive in collaborative environments and love turning challenging business problems into scalable solutions.

Available to hire

Hi, I’m Yamamoto Akio, a Senior Frontend Engineer based in Osaka with 8+ years building scalable, data-driven web apps. I specialize in React, TypeScript, and modern JavaScript, delivering real-time dashboards and interactive UIs that empower users to explore complex data. I’m also comfortable on the backend, having worked with Node.js, Golang, and .NET, and I enjoy bridging the gap between design, engineering, and product to create cohesive experiences.

I’m passionate about mentoring junior developers, contributing to design systems, and improving development efficiency through robust CI/CD, performance optimizations, and thoughtful architecture. I thrive in collaborative environments and love turning challenging business problems into scalable solutions.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

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Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Language

English

Fluent

Japanese

Advanced

Work Experience

Senior Frontend Engineer at Truflation

July 1, 2023 - Present

Built and maintained a Vue 3 + Nuxt + TypeScript component library documented in Storybook; developed responsive UI with Tailwind CSS and Styled Components; optimized performance with code-splitting, dynamic imports, and image optimization; implemented Pinia-based state management and Vue Composition API; integrated APIs and blockchain oracles for real-time inflation data; designed interactive financial visualizations with D3.js and Recharts; led code reviews, set coding standards, and mentored junior developers; improved CI/CD with GitHub Actions, Vitest, and Cypress; ensured pixel-perfect Figma-to-Vue implementations.

Full Stack Engineer at ZenPlus

June 30, 2023 - September 19, 2025

Contributed to ZenPlus, scaling an online marketplace to support 1,000+ Japanese retailers and millions of products; implemented scalable state management with Redux, React Hooks, and Context API for 2,000+ unique states; deployed AWS-based infrastructure (EC2, S3, CloudFront, Route 53) with Redis caching and load balancing for global reach; integrated PayPal, Stripe, Payoneer, and logistics providers; collaborated with cross-functional teams to deliver high-quality software for international growth and multi-language support.

Software Developer at AmeriPlan USA

December 31, 2020 - September 19, 2025

Built and maintained Angular frontend components for member dashboards and back-office tools; designed RESTful backend services in C# / ASP.NET Core for authentication, provider directory operations, and benefit data retrieval; integrated mapping/geolocation features; implemented SSR with Angular Universal to improve SEO and performance; developed unit and integration tests (Jasmine/Karma front-end, xUnit back-end); containerized services with Docker and established CI/CD pipelines in Azure DevOps; collaborated across teams to optimize queries and enhance admin capabilities for coordinators and managers.

Senior Frontend Engineer at Truflation

July 1, 2023 - Present

Built and maintained a Vue 3 + Nuxt + TypeScript component library documented in Storybook; developed responsive UI with Tailwind CSS; optimized Nuxt code-splitting and image handling; implemented Pinia-based state management; integrated APIs and blockchain oracles; built real-time dashboards and designed interactive financial visualizations with D3.js and Recharts; mentored junior developers; enhanced CI/CD with GitHub Actions for Nuxt builds, Vitest unit tests, and Cypress E2E tests; collaborated with design to ensure pixel-perfect Figma-to-Vue implementations.

Full Stack Engineer at ZenPlus

June 1, 2023 - September 19, 2025

Contributed to the ZenPlus online marketplace, scaling the platform to support 1,000+ Japanese retailers and millions of products; enabled global cross-border commerce with multi-language support and no entry or monthly fees for sellers; deployed AWS infrastructure (EC2, S3, CloudFront, Route 53) and improved availability across 150+ countries; integrated PayPal, Stripe, and Payoneer for payments and logistics; implemented a scalable state management architecture (Redux, React Hooks, Context API) to manage 2,000+ states; added Redis caching and AWS load balancing with CloudFront, Auto Scaling, S3, and Route 53; collaborated with backend, UX/UI, and product teams to deliver robust features.

Software Developer at AmeriPlan USA

December 1, 2020 - September 19, 2025

Contributed to the member portal and back-office tools; built frontend components in Angular for member dashboards and backend tools for Benefit Consultants; designed RESTful backend services in ASP.NET Core for authentication, provider directory operations, and plan data retrieval; integrated mapping and geolocation services; developed unit and integration tests (Jasmine/Karma on frontend and xUnit on backend), reducing production defects by ~30–40%; implemented SSR with Angular Universal for SEO and faster initial load; containerized services with Docker and set up CI/CD in Azure DevOps for frequent deployments; participated in code reviews, refactoring, and performance tuning.

Senior Software Engineer at Haver Analytics

July 1, 2023 - Present

Architected and maintained scalable frontend systems using React, TypeScript, and Node.js; built real-time, data-driven economic dashboards; implemented responsive UI with Tailwind CSS and Styled Components; improved performance with Suspense, code-splitting, and dynamic imports; managed state with Redux and Context API; developed real-time data visualizations with D3.js; built RESTful APIs with Node.js/Express; enhanced data security with OAuth and encryption; collaborated with data scientists; introduced Jest and React Testing Library tests; improved CI/CD with GitHub Actions; mentored juniors; contributed to design system and component libraries; partnered with UX/UI to deliver scalable interfaces.

Full Stack Engineer at ZenPlus (ZenGroup Inc.)

June 1, 2023 - October 4, 2025

Contributed to the ZenPlus online marketplace enabling international customers to buy from 1,000+ Japanese retailers. Scaled platform infrastructure with AWS, integrated third-party payment gateways and shipping APIs; implemented NFT-based loyalty programs and wallet authentication using ethers.js and web3.js; prototyped cross-chain payments (Solana, Polkadot, Cosmos SDK); built smart contract prototypes and used Foundry for testing; designed GraphQL APIs and microservices; managed state with Redux; optimized performance with Redis caching and scalable deployment patterns; collaborated across design, backend, and PM teams.

Software Developer at AmeriPlan USA

December 1, 2020 - October 4, 2025

Contributed to member portal and mobile app ecosystem for discount health-benefit plans; built Angular front-end dashboards; designed RESTful services in C#/ASP.NET Core; integrated mapping APIs; optimized query performance; developed tests (Jasmine/Karma for front-end, xUnit for back-end); Dockerized services; set up CI/CD pipelines in Azure DevOps; explored blockchain-backed identity verification and zk-SNARKs for future data portability; enhanced back-office features for Benefit Consultants.

Senior Software Engineer at Haver Analytics

July 1, 2023 - Present

Architected and maintained scalable, modular frontend systems using React, TypeScript, and Node.js to deliver real-time, data-driven economic dashboards. Designed responsive UI components with Tailwind CSS and Styled Components to improve accessibility across devices. Optimized performance with React Suspense, code-splitting, and dynamic imports; implemented Redux and Context API to manage large datasets and real-time updates. Built real-time data visualizations with D3.js; developed RESTful APIs with Express to pull data from internal and third-party sources. Strengthened data security with OAuth and encryption; collaborated with data scientists and analysts to ensure data quality. Introduced Jest and React Testing Library for unit/integration tests and enhanced CI/CD with GitHub Actions. Mentored junior developers and contributed to the design system and component libraries.

Full Stack Engineer at ZenPlus (ZenGroup Inc.)

June 1, 2023 - October 4, 2025

Scaled ZenPlus marketplace infrastructure with AWS (EC2, S3, CloudFront, Route 53, Auto Scaling) to serve 150+ countries with multi-language support. Integrated payment gateways (PayPal, Stripe, Payoneer) and shipping APIs (Japan Post, DHL, FedEx) for global commerce. Implemented NFT-based loyalty and token-gated flows with wallet authentication (ethers.js, web3.js); prototyped cross-chain payments (Solana, Polkadot, Cosmos SDK). Built smart contract prototypes and Foundry tests; designed GraphQL APIs and decoupled payment, inventory, and logistics into microservices. Managed scalable Redux state, and optimized performance with Redis caching, ELB/ALB, CloudFront; collaborated with designers, backend teams, and PMs.

Software Developer at AmeriPlan USA

December 1, 2020 - October 4, 2025

Contributed to member portal and mobile app ecosystem for discount health-benefit plans. Built Angular front-end dashboards for members and Benefit Consultants; designed RESTful services in C#/ASP.NET Core for authentication, provider directories, and plan benefit retrieval. Integrated mapping APIs for provider geolocation and optimized queries for scale. Developed tests (Jasmine/Karma, xUnit); implemented Angular Universal SSR for SEO; containerized services with Docker and set up CI/CD in Azure DevOps. Explored blockchain-backed identity verification and IPFS for data portability; researched zk-SNARKs/zk-STARKs and MPC for private data validation.

Senior Frontend Engineer at Haver Analytics

July 1, 2023 - Present

Architected and maintained scalable, modular frontend systems using React and TypeScript to build real-time, data-driven economic dashboards. Implemented responsive UI components with Tailwind CSS and Styled Components to improve accessibility across devices. Optimized performance with React Suspense, code-splitting, and dynamic imports; managed state with Redux and Context API for large datasets and real-time updates. Built real-time data visualizations with D3.js and collaborated with data scientists and backend teams to ensure seamless API integration. Contributed to design systems, improved CI/CD pipelines with GitHub Actions, and mentored junior frontend developers.

Full Stack Engineer at ZenPlus (ZenGroup Inc.)

June 1, 2023 - October 4, 2025

Contributed to the ZenPlus online marketplace, enabling international customers to buy from 1,000+ Japanese retailers. Scaled platform infrastructure on AWS (EC2, S3, CloudFront, Route 53, Auto Scaling), integrated PayPal/Stripe/Payoneer and logistics APIs, and implemented NFT-based loyalty programs with wallet authentication (ethers.js, Web3.js). Prototyped cross-chain payments (Solana, Polkadot, Cosmos SDK); built smart contract prototypes and tested with Foundry. Designed GraphQL APIs for seller/product queries and architected microservices to decouple payment, inventory, and logistics. Optimized state management with Redux and maintained Redis caching; collaborated across teams to deliver scalable features.

Software Developer at AmeriPlan USA

December 1, 2020 - October 4, 2025

Contributed to member portal and mobile app ecosystem for discount health-benefit plans, enabling provider search, prescription savings, and household management. Built Angular front-end dashboards for members and tools for Benefit Consultants, designed RESTful services in ASP.NET Core, integrated mapping APIs for provider geolocation, and optimized queries for scale. Implemented SSR with Angular Universal to improve SEO and initial load speed; containerized services with Docker and established CI/CD pipelines in Azure DevOps. Explored blockchain-backed identity verification and decentralized storage concepts for future data portability.

Senior Frontend Engineer at Haver Analytics

July 1, 2023 - Present

Architected and maintained scalable, modular frontend systems using React, TypeScript, and modern best practices to build real-time, data-driven economic dashboards. Designed responsive UI components with Tailwind and Styled Components, improving accessibility and usability for users interacting with complex time-series data. Enhanced frontend performance with Suspense, code-splitting, and dynamic imports. Implemented state management with Redux and Context API to handle large datasets and real-time updates. Built real-time data visualizations with D3.js and other libraries. Collaborated with UX/UI, data science, and backend teams to ensure seamless API integration and design system consistency. Implemented automated tests with Jest and React Testing Library; contributed to CI/CD pipelines with GitHub Actions; mentored junior developers.

Full Stack Engineer at ZenPlus

June 1, 2023 - October 4, 2025

Contributed to the ZenPlus online marketplace by ZenGroup Inc., enabling international customers to buy directly from 1,000+ Japanese retailers. Scaled platform infrastructure on AWS (EC2, S3, CloudFront, Route 53, Auto Scaling) to serve 150+ countries with multi-language support. Integrated third-party payment gateways (PayPal, Stripe, Payoneer) and shipping APIs (Japan Post, DHL, FedEx). Implemented NFT-based loyalty programs and wallet authentication using ethers.js and web3.js; prototyped cross-chain payments (Solana, Polkadot, Cosmos SDK). Built smart contract prototypes and conducted Foundry testing. Explored DAO governance models with Snapshot and Aragon. Designed GraphQL APIs and decoupled payment, inventory, and logistics flows with microservices. Managed state with Redux and React Hooks; optimized performance with Redis caching and load balancing. Collaborated with designers, backend teams, and PMs to deliver scalable features.

Software Developer at AmeriPlan USA

December 1, 2020 - October 4, 2025

Contributed to the member portal and mobile app ecosystem for discount health-benefit plans, enabling provider search, prescription savings, and household management. Built Angular front-end dashboards for members and tools for Benefit Consultants; Designed RESTful services in C#/ASP.NET Core for authentication, provider directories, and plan benefit retrieval. Integrated mapping APIs for provider geolocation and optimized queries to scale user lookups. Developed tests (Jasmine/Karma for frontend, xUnit for backend) reducing production defects by ~30–40%. Implemented SSR with Angular Universal to improve SEO and initial load speed. Containerized services with Docker and configured CI/CD pipelines in Azure DevOps. Researched blockchain-backed identity verification and IPFS-based decentralized storage for future health data portability; explored zk-SNARKs and zk-STARKs for private data validation.