João Amadeu
Verified Expert in Engineering
Software Developer
Porto, Portugal
Toptal member since November 22, 2021
João is a versatile software engineer specializing in back-end services, APIs, and full-stack web and mobile development. With deep expertise in TypeScript, Go, Node.js, React, and React Native, he builds scalable, high-performance applications. Recently, João’s expanded into AI, creating intelligent agents with OpenAI and Cla. He's ready to bring smart, efficient solutions to future projects.
Portfolio
Experience
- React - 6 years
- Full-stack - 5 years
- Node.js - 5 years
- React Native - 4 years
- Amazon Web Services (AWS) - 4 years
- Git - 3 years
- OpenAI - 3 years
- Large Language Models (LLMs) - 2 years
Work Experience
Software engineer
Bisect
- Built a canvas tool to let users arrange and manage a Multi-viewer stage by dragging and dropping nodes, scaling, rotating, and aligning them.
- Created a real-time flowchart to let users visualize how decoders and encoders are connected in the network.
- Refactored and migrated an old Angular app with Next.js and TypeScript.
Senior JavaScript Developer
Kerico Home Clinic Services LLC
- Built a mobile app with React Native to handle patients' transportation.
- Tracked and fixed bugs using the Sentry reporting tool.
- Developed a web admin to manage users and drivers and eliminate manual work.
Senior Front-end Engineer
Statement Mc
- Developed a trading platform to exchange large quantities of food.
- Built a pixel-perfect UI using Figma to showcase an intern product with Chakra UI.
- Created an HR application to facilitate the company recruiting process.
Senior React Native Developer
The Skins App, Inc.
- Refactored some style issues and improved the user experience for an innovative MVP app.
- Helped find small things in the app to be able to release a better MVP.
- Worked with GraphQL to reduce the amount of data coming from the server.
React Native Developer
L`École AI, INC
- Implemented the new React Native FlashList component to obtain more performance while rendering more than a 1000 images.
- Created a custom function to fetch images from AWS S3 service and render them on the app.
- Refactored some parts of the app and added TypeScript support.
- Used the new Expo EAS Service to publish and share the app with the client.
React Front-end Developer
Toptal
- Migrated a legacy UI to React with TypeScript and MUI, improving the codebase to consume the data from the server.
- Developed an API and hosted it on Heroku to manage and connect it with the front end.
- Migrated a trading advisory robot MVP (built with Python) that helps clients trade to a Node.js RESTful API.
Front-end Developer
Let's Delivery
- Migrated the style codebase from Sass to styled-components and TypeScript.
- Redesigned the entire app to a modern, pixel-perfect UI/UX based on Adobe XD designs.
- Collaborated with the design team and used AWS S3 to share, test, and approve the new UI.
Full-stack Developer
Hero99
- Improved the performance and data sharing between nested components by adding RTK Query to fetch, cache, and update server data.
- Added some custom utils React Hooks with TypeScript to a codebase resulting in less duplicated logic working with the Boolean data.
- Improved components rendered by separating them into small ones.
Front-end Developer
Spaceman
- Automated the static page content editing process by connecting Contentful with the Next.js application.
- Improved security in the DApp by adding a higher-order component (HOC) and server-side verification to check wallet connection and user permissions.
- Wrote a Telegram bot in Node.js and Express.js to provide cryptocurrency information from the Ethereum network. Hosted it at Heroku.
Front-end Developer
SNIR
- Improved server data fetch, cache, and updates by using React Apollo and Axios to perform GraphQL requests.
- Designed a new codebase for my entire team using Next.js, TypeScript, and GraphQL.
- Improved a client global state management between nested components by adding a new React Context API.
Full-stack Engineer
Freelance | Self-employed
- Developed a web application for an educational institution and automated their activities by 80%.
- Built pixel-perfect web apps for small restaurants to manage their business.
- Developed a startup website named Alien Space at 66alienspace.com.
Project History
Homus
Skills
Libraries/APIs
React, Node.js, React Redux, React Query, Socket.IO, Stripe, REST APIs, Chart.js, GitHub API, React Native for Web, Stripe API, Formik, React Testing Library, Web3.js, Telegram Bot API, Context API, Reactstrap, React Navigation, Emotion Library, AWS Amplify, AmplifyJS, Redux-Saga, Trello API, YouTube API, Facebook API, Instagram API, TikTok API
Tools
Git, GitHub, Figma, Jira, JSX, Expo.io, Redux Toolkit, Prisma, NPM, Claude Code, TanStack Router, Expo, Trello, Notion, Slack, Auth0, Claude, Drizzle ORM, React Apollo, MongoDB Atlas, MetaMask, Amazon Cognito, Sentry, AWS Command Line Interface (CLI), Xcode
Languages
TypeScript, JavaScript, GraphQL, HTML, CSS, SCSS, SQL, ECMAScript (ES6), Go, Sass, HTML5, CSS3, Python, Coolify, Rust, PHP
Frameworks
React Native, Express.js, Next.js, Material UI, Bootstrap, Tailwind CSS, Redux, JSON Web Tokens (JWT), Jest, NestJS, Electron
Paradigms
REST, Testing, UI Design, Web UI Design, Clean Code, Azure DevOps, Unit Testing, Marketplace Platforms, B2B, Mobile Development, Back-end Architecture, Scrum, Kanban, Business Intelligence (BI)
Platforms
Contentful, iOS, Visual Studio Code (VS Code), Docker, Vercel, Amazon Web Services (AWS), Azure, Android, Mapbox, Blockchain, Linux, Heroku, Netlify, Firebase
Storage
PostgreSQL, Databases, JSON, MongoDB, Redis, Amazon S3 (AWS S3), Hasura, MySQL
Other
MacBook, Styled-components, Full-stack, API Integration, Responsive Web Apps, WebSockets, Front-end, APIs, Apollo, Application State Management, Mobile App Development, User Interface (UI), User Experience (UX), Responsive Design, Front-end Development, Web Development, Dashboards, Front-end Architecture, Front-end Design, Mobile First, Full-stack Development, Responsive UI, AI Tools, Cursor AI, AI Integration, Streaming Data, Payment APIs, Software Development, Mobile UI, Supabase, Vibe Coding, App Design, Data Modeling, Web Applications, Design, Storybook, OAuth, Back-end, Back-end Development, Architecture, Mobile Apps, Mobile UX, Payment Gateways, eCommerce, 3D, UI Components, Web3, Maps, Subscriptions, Apple Pay, CI/CD Pipelines, OpenAI, Large Language Models (LLMs), JWT Authentication, Concurrency, Event-driven Systems, Software, Server Sent Events (SSE), Real Estate, Performance Optimization, Software Architecture, System Architecture, Optical Character Recognition (OCR), Technical Leadership, Chromium, Auditing, Security, Discord, Axios, Gatsby, Ethers.js, Google+ Authentication, Chakra UI, Domain-driven Design (DDD), Mirage, Webhooks, Prismic, Telegram Bots, Atomic Design, Content Management Systems (CMS), Leadership, Teams
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