César Antunes
Verified Expert in Engineering
Front-end Developer
César has four years of experience as a professional front-end developer. His expertise includes Angular, React, .NET, and other frameworks. César's current focus is on React and its newest features and tools such as TypeScript, Sass, Enzyme, Cypress, and Next.
Portfolio
Experience
Availability
Preferred Environment
Linux, GitHub, Git, Postman, Chrome, Visual Studio Code (VS Code), MacOS
The most amazing...
...thing I've developed is a webinar application, a platform to create and schedule live webinars using YouTube or Vimeo.
Work Experience
Senior Full-stack Developer
Plank
- Led and developed and app that connects to a physical health monitoring device via Bluetooth, send metrics to the backend and display processed metrics as graphs, using React Native with Expo, Typescript and Native Wind.
- Developed an API using Express, Prisma, and PostgreSQL, following the Clean Architecture principles. Led and developed an app that connects to a physical health monitoring device via Bluetooth, sends metrics to the back end, and displays processed metrics as graphs, using React Native with Expo, TypeScript, and NativeWind.
- Integrated the app and Auth0 using Auth0 Management API through our own API.
Senior Front-end Developer
meutudo.
- Maintained and improved the main company's mobile app using React Native, TypeScript, and Redux and testing using Jest and React Testing Library.
- Led the junior front-end developers of the team by helping them improve technically, keeping track of their contributions, and ensuring code quality and reliability.
- Architected, led, and maintained the company's component library, using the same codebase in the React Native mobile app and React web applications. Led junior main contributors of the library and designed best practices for external contributors.
Front-end Developer
AtomicVest Inc
- Maintained and improved an embedded app for investment and shares market, using React, TypeScript, and modern tools to convert Figma files into screens/components.
- Created a Node.js SDK based on an OpenAPI schema JSON file. The library generates all the code by the schema file using Axios and typed methods. Developed a workflow that automatically updates the version every time the schema file gets updated.
- Converted an old dashboard web app from Next.js to React using the most recent technologies.
Front-end Developer
BILDIT
- Maintained and improved the company's CMS dashboard web application using Jira as a reporting tool.
- Migrated JavaScript code to TypeScript, which included mapping all data types and replacing React PropTypes with TypeScript types.
- Improved the performance of the data table pages by implementing pagination in the back-end side and transferring filter and ordering logic from the front end to the back end.
- Proposed a new pattern to define Redux's actions and reducers which rendered it simpler and more type-safe and more appropriate for the new TypeScript environment.
Front-end Developer
Belk
- Contributed to the refactoring of the eCommerce app from native code to a single React Native project.
- Proposed new architecture types and code organization techniques to improve code quality regarding navigation, forms, and UI elements.
- Developed performance improvements in the product list which removed 80% of app crashes on this screen.
Freelance Developer
Freelance
- Worked on a music mobile app, using React and Ionic, and later refactored it to React Native. The app was written in TypeScript, using Redux-saga and Video.js.
- Developed an npm package to manage the UI elements of a company. The work involved refactoring the React components, from JavaScript to TypeScript and from Sass to Emotion CSS, and migrating their implementation to an npm package.
- Worked as a front-end developer on a mobile shop app using React Native, TypeScript, and Redux-saga.
Front-end Developer
Hotmart
- Developed SPAs using React, TypeScript, Sass, and Redux, and the newest features of React such as Hooks, memo, refs, and the Context API.
- Created forms using React, Yup, and React Hook Form.
- Developed React component libraries using React, TypeScript, and Sass, and published them in Hotmart's private NPM repository.
- Improved the browser performance of a chat web component, using React component memoization, list virtualization, and event throttling using Lodash.
- Rewrote a Node.js server application using Socket.IO. The previous implementation had several memory leaks and performance issues. A new module architecture solved the problem.
- Completed end-to-end tests using Cypress, and included this as a step in continuous deployment using Drone.
Front-end Developer
Usemobile
- Developed admin dashboards for mobility apps, using AngularJS.
- Built a module to monitor a driver's position and route, using JavaScript and Google Maps API.
- Developed websites using .NET Framework and built a search module for school buildings that uses text as the region, using JavaScript and Google Maps API.
- Created a desktop application using AngularJS and Electron.js.
Game Developer
Meatballs Digital Brunch
- Developed a game using Unity3D. Users could access the game through a webpage and product key, and the game was controlled by the webpage using WebSockets.
- Created an animation to run in Oculus Rift using Unity3D.
- Built an AR application using Unity3D to preview a neighborhood mockup while pointing the device camera to the company logo.
Experience
Portal Web Page for Kumon Schools
https://www.kumon.com.br/Front-end of Lyra Music App (via Toptal)
https://play.google.com/store/apps/details?id=com.lyramusic.appFront-end Development at Strive Talent, Inc. (via Toptal)
• Updated the style of the components following the design provided by the client.
• Converted React components from JavaScript to TypeScript, creating useful types and interfaces and proposing good practices.
• Converted React component styles from Sass to Emotion CSS.
Skills
Languages
JavaScript, TypeScript, CSS, HTML, HTML5, Sass, SCSS, C#.NET, C#, Swift, Java, SQL, GraphQL
Frameworks
Unity3D, Redux, AngularJS, Cypress, React Native, Next.js, Electron, Chrome, .NET, Jest, Ionic, Ionic 3, Video.js, Tailwind CSS, Koa, Material UI, Express.js
Libraries/APIs
React, Node.js, Socket.IO, Google Maps, Emotion Library, MobX, Yup, React Redux Form, CocoaPods, Redux-Saga, D3.js, React Testing Library, Auth0 API, REST APIs
Other
Front-end, Enzyme, i18n, Sagas, Storybook, Computer Science, Game Development, Multilingual Websites, CSS Modules, WebSockets, RPC, Styled-components, GitHub Actions, Axios, Supabase, Full-stack, Web Development, Mobile App Development
Tools
Blender, GitHub, Git, Sublime Text, Postman, Webpack, CircleCI, NPM, Redux Thunk, Figma, Bitbucket, Reactotron, LaunchDarkly, Auth0, Photoshop CS5, Adobe Experience Design (XD), Lerna, Expo, Prisma
Paradigms
Kanban, Mobile Development
Platforms
Drone CI, Visual Studio Code (VS Code), Windows, Heroku, Linux, MacOS, Bitrise, Firebase
Storage
Amazon S3 (AWS S3), PostgreSQL
Education
Bachelor's Degree in Computer Science
Federal University of Ouro Preto - Ouro Preto, Minas Gerais, Brazil
Bachelor of Technology Degree in Game Development
Pontifical Catholic University of Minas Gerais, PUC-MG - Belo Horizonte, Minas Gerais, Brazil
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring