Haruto Inoue, Developer in Toronto, ON, Canada
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Haruto Inoue

Verified Expert  in Engineering

Software Developer

Toronto, ON, Canada
Toptal Member Since
April 2, 2020

Haruto is a highly efficient and reliable professional with a broad web application development skill set. He's been working on a range of products and clients. His work involves working on production teams to maintain eCommerce applications, designing front-end architecture and building front-end apps from scratch. Haruto's main skill sets include JavaScript, TypeScript, React, Next.js, Redux, and Node.js.


React, Node.js, PostgreSQL, JavaScript, HTML, CSS, Reactor...
Midas Capital
Solidity, Web3.js, Ethers.js, JavaScript, TypeScript, Hardhat, Ethereum...
Mawoo Pets
JavaScript, TypeScript, React, Storybook, Next.js, CSS, HTML, GraphQL...




Preferred Environment

Skype, Slack, Trello, Asana, Jira, Bitbucket, Git, Visual Studio Code (VS Code), Linux

The most amazing...

...things I've developed are responsive front-end UIs, back-end API endpoints, and third-party integrations.

Work Experience

Senior Software Engineer

2023 - 2023
  • Developed a supply chain management platform dashboard.
  • Worked on purchase order item management, audit trail management, and status tracking.
  • Worked with UI/UX designers to add new design implementation.
  • Refactored legacy front and back-end code in React and Node.js.
Technologies: React, Node.js, PostgreSQL, JavaScript, HTML, CSS, Reactor, Amazon Web Services (AWS), Auth0 API, Auth0 Management API v2, Redux, Redux-Saga, Full-stack, SQL, Git, Express.js

Full-stack Engineer

2021 - 2022
Midas Capital
  • Worked closely with graphic UI/UX designers to translate their wireframes into pixel-perfect, responsive components and pages.
  • Wrote JavaScript and TypeScript SDK library that can be consumable from the client side.
  • Wrote the front-end UI/UX automation and unit testing with Jest and Cypress.
  • Worked on Oracle integrations for multiple protocols like Uniswap and Chainlink.
  • Wrote smart contracts for decentralized finance strategies like borrowing and lending on multi-chain support for BSC, Polygon, and Moonbeam.
  • Integrated a liquidator provider for multiple decentralized finance protocols with ERC-4626.
  • Created tests for smart contracts with Foundry based on forked mainnet environments.
  • Implemented the script for upgradeable smart contracts and deployed it into multiple networks.
Technologies: Solidity, Web3.js, Ethers.js, JavaScript, TypeScript, Hardhat, Ethereum, Amazon Web Services (AWS), Next.js, Node.js, Chakra UI, ApexCharts.js, TypeScript 3, API Integration, Full-stack, SQL, Git, CSS, Express.js

Senior Front-end Engineer

2020 - 2022
Mawoo Pets
  • Designed the front-end architecture and solutions, improved the front-end UI/UX performance, and provided technical solutions for products.
  • Worked with UI/UX designers and built pixel-perfect, responsive, and smart UI/UX implementation with React.
  • Built a front-end components library with React and Storybook, writing unit and E2E tests with Jest and Cypress.
  • Built a data analytical dashboard, displaying sales data for customers and breeders with D3.js.
  • Added a Google Map view in the puppy search view and customized the Google Map view and chat integration with SendBird.
  • Attended product meetings to discuss business directions and UI/UX feature discussions with designers.
  • Collaborated with back-end developers to consume APIs and wrote GraphQL queries and mutations on GraphQL endpoints.
  • Mentored and onboarded junior front-end developers, reviewing PRs for other developers.
Technologies: JavaScript, TypeScript, React, Storybook, Next.js, CSS, HTML, GraphQL, Tailwind CSS, Apollo, Jest, Cypress, D3.js, Google Maps, Google Maps API, API Integration, Front-end, Git

Full-stack Engineer

2019 - 2022
  • Built sophisticated, smart contracts like staking marketplace offers, troubleshot production issues, contributed to gas fee optimization, and deployed them into the Ethereum mainnet.
  • Migrated smart contracts from Ethereum to Polygon and existing assets (NFTs, offers, and collections) to newly deployed contracts on Polygon.
  • Performed a Web3 integration with the smart contracts on Next.js.
  • Built subgraph endpoints to interact with smart contract-triggered events and deployed them into the graph protocol.
  • Worked closely with other protocols like Rarible, Aave, and Compound.
  • Built front-end UI/UX pages with Next.js and React with Tailwind CSS and styled components from the Figma design.
  • Built back-end Node.js services for a basic front-end integration hosted on AWS Lambda.
Technologies: Solidity, Ethereum, Polygon, Web3.js, Subgraph, React, Next.js, GraphQL, Tailwind CSS, Vue, Nuxt.js, Amazon Web Services (AWS), Docker, Node.js, API Integration, Front-end, Full-stack, SQL, Git, CSS, JavaScript

Back-end Engineer

2021 - 2021
SimpleTire LLC
  • Collaborated with back-end developers in the two-week sprint.
  • Cooperated with Sonata admin and Symfony components for building and updating the back office site.
  • Wrote unit test cases for the admin classes with PHP Phake.
Technologies: JavaScript, PHP 7, Symfony, GitHub, Jenkins, VirtualBox, Jira, Sonata, API Integration, Full-stack, SQL, Git

Nuxt.js Developer

2020 - 2021
Music Getaways LLC
  • Built front-end ads pages with Nuxt.js and Tailwind CSS.
  • Added models and data into Contentful and showed them on front-end pages.
  • Integrated Mailchimp subscription for various audiences.
  • Integrated a pixel-perfect and responsive UI/UX based on an Invision design.
Technologies: JavaScript, Vue, Nuxt.js, Contentful, Headless CMS, Tailwind CSS, InVision App, Slack, Mailchimp, API Integration, Front-end, Git, CSS

Next.js Developer

2020 - 2021
  • Developed CMS components (editable) based on React and Next.js.
  • Troubleshot existing errors and added new features.
  • Communicated with the front and back end through GraphQL endpoints.
  • Handled global state management with Redux (Redux Toolkit).
  • Worked with TypeScript, updating from JavaScript to TypeScript.
Technologies: React, Next.js, Amazon Web Services (AWS), GraphQL, Redux, JavaScript, Skype, APIs, TypeScript, Docker, MySQL, Hasura, API Integration, Front-end, Git, CSS

Full-stack Developer

2020 - 2020
Mountain Internet Group, LLC
  • Updated front-end UI components and troubleshooting.
  • Fixed production issues and added new features to production.
  • Updated legacy back-end code and crawler logic on a microservice.
Technologies: Amazon Web Services (AWS), Microservices, CI/CD Pipelines, Slack, Trello, PHP 7, MySQL, Web Crawlers, Docker, JavaScript, Vue, Laravel, Tailwind CSS, API Integration, Front-end, Full-stack, SQL, Git, CSS, Express.js

Full-stack Developer

2020 - 2020
DataTape Inc.
  • Supported building pixel-perfect front-end UIs with React.
  • Implemented an online real-time chat with SendBird.
  • Wrote back-end API endpoints with Node.js and AWS integration, notably S3.
  • Worked with PostgreSQL as a DB using Objection and knex.
  • Used Jira for issue tracking and Slack for communication.
Technologies: Amazon Web Services (AWS), Firebase, Node.js, React, HTML, CSS, Styled-components, API Integration, Front-end, Full-stack, Git, Express.js, JavaScript

Senior Full-stack Developer

2017 - 2019
ACI Plastics
  • Built, designed, and implemented high-volume, high-scale responsive web front ends, web APIs, and data analytics solutions in the cloud.
  • Cooperated with the back-end team in their development of RESTful APIs.
  • Built user interfaces for a re-imagined user experience using React and Node.js.
  • Implemented a pixel-perfect, responsive, and smart front-end UI.
  • Contributed to the development of our next-generation SaaS products.
Technologies: Amazon Web Services (AWS), Bitbucket, Slack, Jira, APIs, GraphQL, RxJS, Vuex, Redux, Vue, Angular, React, Node.js, API Integration, Front-end, Full-stack, SQL, Git, CSS, Express.js, JavaScript

Lead Developer

2012 - 2017
LTI Trucking Services
  • Coordinated with customer support to respond quickly to issues for users and solve those in a permanent and scalable way.
  • Provided input to business analysts and system analysts during the requirements-gathering stage.
  • Tested code using various techniques, including manual and automated unit tests, functional testing, and regression tests.
  • Maintained code integrity, branches, and migration within source control.
  • Wrote high-quality, efficient, and testable code in JavaScript.
  • Took the initiative and developed approaches and solutions to software problems.
Technologies: Amazon Web Services (AWS), Git, Jira, Slack, PostgreSQL, Express.js, Node.js, Redux-Saga, Redux, React, JavaScript, API Integration, Front-end, Full-stack

Full-stack Engineer

2010 - 2012
  • Developed specifications and designs for complex applications and maintained complex existing applications.
  • Collaborated with other team members on production issues.
  • Built APIs and data delivery mechanisms for applications such as dashboards, mobile apps, and third-party integrations.
  • Collaborated with product managers using Agile methodologies to deliver high-quality products on time.
Technologies: Express.js, Bootstrap, jQuery, Node.js, JavaScript, API Integration, Front-end, Full-stack, SQL, CSS

Mawoo Pets

Mawoo Pets is an eCommerce platform selling puppies for breeders in US and Canada. As a senior front-end engineer, I was mainly responsible for UI/UX implementation, working closely with graphic designers and collaborating with back-end engineers to consume GraphQL endpoints in the front end. I also wrote automatic tests with Jest and Cypress.

Smile Direct Club

It provides users with the convenience of making it easy to buy aligners without the need to visit an office. I worked as a full-stack developer and built the project with React and Node.js. I played a key role in building reusable and testable components, managing database for the back-end part, and processing other images.


A website selling Tempur-Pedic products online. It was built with the MERN stack, and I worked as a front-end developer on this project. I mainly developed responsible and smart UI components and local state management.


HTML, CSS, TypeScript, JavaScript, SQL, ECMAScript (ES6), Python, Go, Java, Python 2, Python 3, GraphQL, PHP 7, Solidity, Rust, TypeScript 3


MUI (Material UI), Serverless Framework, ASP.NET, Laravel, Symfony, Next.js, Nuxt.js, Cypress, Angular, Express.js, Redux, Vuetify, Jest, .NET, .NET Core, Spring Boot, Django, Flask, Bootstrap, Tailwind CSS, Electron


React, Node.js, Vue, jQuery, Vuex, Redux-Saga, Reactstrap, Formik, React Router, D3.js, RxJS, Backbone.js, Antd, Chai, Web3.js, MobX, ApexCharts.js, Google Maps, Google Maps API, Reactor, Auth0 API, Auth0 Management API v2


CircleCI, NPM, Vue CLI, Angular CLI, Sublime Text 3, Atom, Git, Bitbucket, Jira, Asana, Trello, Redux Thunk, Solr, Mocha, Slack, Skype, Mailchimp, GitHub, Jenkins, VirtualBox, React Apollo


Serverless Architecture, Unit Testing, Microservices, Microservices Architecture, Test-driven Development (TDD), DRY, Behavior-driven Development (BDD)


Amazon EC2, AWS Lambda, MacOS, Ubuntu Linux, Visual Studio Code (VS Code), Amazon Web Services (AWS), Docker, Linux, Heroku, Firebase, Blockchain, Ethereum, Contentful


Amazon S3 (AWS S3), MySQL, MongoDB, PostgreSQL, Redis, Elasticsearch, Hasura


Serverless, Gatsby, Front-end, Back-end, Full-stack, APIs, Axios, Web 3.0, API Integration, Ubuntu Server, Enzyme, Web Crawlers, CI/CD Pipelines, Headless CMS, InVision App, Sonata, Polygon, Subgraph, Ethers.js, Hardhat, Styled-components, Chakra UI, Storybook, Apollo, Software, Computer Science

2006 - 2010

Bachelor of Engineering Degree in Computer Science

Osaka University - Osaka, Japan