André Castelo, Developer in João Pessoa, Paraíba - State of Paraíba, Brazil
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André Castelo

Verified Expert  in Engineering

Mobile Web Developer

João Pessoa, Paraíba - State of Paraíba, Brazil
Toptal Member Since
August 29, 2016

André is a software engineer focusing on front-end development, with years of experience building JavaScript applications using React. He has also worked on several full-stack projects using PHP and Python, leveraging tools such as Laravel, Django, and FastAPI to deliver quality products.


TypeScript, React, Next.js, Python, FastAPI, Django, Django REST Framework...
React, Redux, TypeScript, Node.js, Express.js, Redux-Saga, Formik, Terraform...
Cyral Inc
Mobile Web, User Interface (UI), User Experience (UX), Material UI...




Preferred Environment

Git, MacOS, Neovim, Tmux

The most amazing...

...project I worked on was an AI-based email dispatcher that allowed trucking companies to ask for loads by email and get them automatically.

Work Experience

Senior Software Engineer

2022 - PRESENT
  • Improved the performance of the web platform by reducing the time it takes for the pages to load from six seconds to less than one second.
  • Built an AI-based product that increased the transactions one of the beta clients made through the platform from 8% to 22%.
  • Built an API to consume public government data and provide information on trucking companies. This API was responsible for significantly speeding up the sales pipeline in the following months.
Technologies: TypeScript, React, Next.js, Python, FastAPI, Django, Django REST Framework, SQLAlchemy, PostgreSQL, PostGIS, Docker, CircleCI, GitHub Actions, Redux, Formik, Material UI, APIs, CSS, Firebase, HTML, Styled-components, Continuous Integration (CI), Front-end

Senior Software Engineer

2021 - 2022
  • Architected and built from the ground up the main front-end dashboard using TypeScript, React, and Redux, as well as maintaining the Terraform and Docker configurations for the front-end applications.
  • Wrote end-to-end tests using the Playwright library, also using them to monitor stability and availability of the production environment with smoke tests.
  • Integrated Keycloak authentication (PKCE) in our main application, with multi-tenancy support in the front end. Different clients would provide different auth realms to their users.
  • Monitored and fixed issues using a combination of Sentry and Kibana, with Linear as our reporting tool.
  • Architected and built from the ground up our platform dashboard and platform gateway service. The gateway was in charge of communicating with the Kotlin back end and preventing complex logic from being added to the front end.
  • Built and maintained internal packages used by our front-end team to improve consistency across our multiple front-end applications.
  • Mentored our junior front-end developers with code reviews and pair programming.
  • Documented the apps and libraries extensively using Notion and markdown files in our codebase, iterating on those to improve onboarding of new developers, asynchronous communication, and developer experience.
Technologies: React, Redux, TypeScript, Node.js, Express.js, Redux-Saga, Formik, Terraform, Docker, Material UI, Playwright, E2E Testing, RTK Query, Kibana, Sentry, Grafana, GitHub Actions, Continuous Deployment, Continuous Integration (CI), Yarn Workspaces, Monorepos, Keycloak, Notion, CSS, HTML, Styled-components, APIs, Front-end

Senior Front-end Developer

2020 - 2020
Cyral Inc
  • Developed and iterated over the design for several pages and components, focusing on making the interface easier for users while also making it look good.
  • Implemented Emotion, a CSS-in-JS library, into the project to improve the organization and readability of the CSS code for the project.
  • Added code quality enforcing tools to ensure that the codebase had a consistent style and that no syntax errors were committed.
Technologies: Mobile Web, User Interface (UI), User Experience (UX), Material UI, Emotion Library, React, JavaScript, Keycloak, CSS, HTML, Styled-components, Front-end

Front-end Developer

2020 - 2020
  • Avoided using Redux or GraphQL for complex state management by using React Hooks and React Contexts intelligently.
  • Implemented a complete redesign of the clients's dashboard, focusing on component reusability and readability while making sure it matched the design closely.
  • Implemented CSS-in-JS library Emotion to help organize the styling and minimizing repeated code as much as possible.
  • Worked with other developers to create an appropriate style guide for the codebase, and used Git hooks and other tools to enforce it.
Technologies: Mobile Web, JavaScript, Emotion Library, React, CSS, HTML, Front-end

Front-end Developer

2019 - 2020
Coolfire Solutions
  • Implemented several components according to specifications and worked closely with the designer to make sure they matched the InVision designs.
  • Worked on a client's dashboard, where the user was able to create data streams and manage their networks with ease.
  • Made several improvements to UX to make the dashboard as intuitive as possible.
  • Worked closely with the other developers reviewing code, writing tests and fleshing out front-end architecture.
Technologies: Mobile Web, TypeScript, JavaScript, Styled-components, Apollo, GraphQL, React, CSS, HTML, Front-end

Front-end Developer

2019 - 2019
Vault Health
  • Implemented many components related to their website redesign, focusing on responsive design and ensuring the layout was pixel perfect in all of the required resolutions.
  • Restructured their patient information quiz to allow the marketing team to deploy different quizzes and A/B test them for optimal engagement.
  • Worked closely with the designer and the other developers to ensure a quality delivery.
Technologies: Mobile Web, JavaScript, Emotion Library, TypeScript, Redux, React, CSS, HTML

Front-end Developer

2018 - 2019
Listing Loop
  • Created several high-fidelity React components according to the design approved by the client.
  • Refactored several existing components and created new ones to ensure the platforms were compatible with mobile.
  • Improved performance on several areas of the application by simplifying code, implementing pagination, and extracting components.
Technologies: Mobile Web, JavaScript, Firebase, Rollup, TypeScript, Redux-Saga, Redux, React, CSS, HTML, APIs, Front-end

Web Developer

2017 - 2018
Grin, Inc.
  • Worked on a feature to create email sequences that are automatically sent based on current relationship status with an influencer.
  • Implemented scheduled jobs to send pending campaign emails.
  • Maintained the front and back end and fixed bugs.
Technologies: PHP, JavaScript, MySQL, Elasticsearch, Forge, Envoyer, Vue, Laravel, PHP 7, HTML, APIs, Front-end

Back-end Developer

2017 - 2017
Daring Development
  • Created the API test suite with HTTP and unit tests as well as tests for the most critical parts of the application.
  • Integrated the API with Discord—every time a new pro user registers on our application, we add him to the correct Discord server with the correct roles and username. This was achieved using the Laravel scheduler, Socialite, and the Discord API.
  • Overhauled the way users vote for which games they want cheats for.
  • Worked completely in the back end with Laravel 5.4.
Technologies: PHP, MySQL, Laravel, PHP 7, APIs

PHP/JavaScript Developer

2016 - 2017
ContentLaunch (via Toptal)
  • Worked on getting Twitter, Facebook, WordPress, Writer Access, and Stripe integrations up and running.
  • Integrated the app with Amazon S3.
  • Implemented the accounts feature, making it easier for users to collaborate with each other on content while allowing agencies to better handle their business accounts.
Technologies: PHP, JavaScript, Vue, Sass, Laravel, PHP 7, CSS, HTML, APIs, Front-end

Web Developer

2016 - 2016
WPensar Group
  • Worked closely with designers and other developers to deliver top quality interfaces.
  • Created an end-to-end testing suite using Behave and Selenium to ensure the quality of the user experience.
  • Wrote endpoints for our API to deliver new functionality for our customers.
  • Wrote a unit testing suite for our front-end application to guarantee the consistency and quality of critical features.
  • Optimized the front-end build pipeline using Gulp.js, JavaScript linters, and the TypeScript compiler.
Technologies: JavaScript, Gulp, TypeScript, AngularJS, MySQL, Django REST Framework, Python, Django, CSS, HTML, APIs, Front-end

Web Developer and Software Architect

2013 - 2016
Estrategia Marketing Digital
  • Worked on several legacy CodeIgniter projects, keeping them up to date and modernizing the codebase.
  • Deployed multiple PHP applications written in Laravel and CodeIgniter.
  • Developed RESTful APIs using CodeIgniter and Laravel.
  • Worked closely with designers to deliver innovative interfaces and experiences.
  • Planned and implemented architecture and databases for several clients.
Technologies: MySQL, Mobile Web, Vue, jQuery, JavaScript, Grunt, Gulp, PHP, Sass, AngularJS, Laravel, CSS, HTML, APIs, Front-end

Vault Health
Vault Health delivers a unique solution to health issues that plague men of all ages. I was involved in the redesign of their main website, as well as implementing some key functionalities related to their patient care dynamic forms.

The project was built using React, Redux, TypeScript, and some CSS-in-JS using Emotion.

Listing Loop Platform
Listing Loop aimed to connect buyers and real estate agents in the Australian market, with a very unique approach. The UI and UX was a great challenge, involving responsive design, maps, dynamic components and a lot of interaction.

The tech stack consisted of React, Redux, TypeScript, Styled System and Styled Components, and Firebase in the back end. There were many challenges with data handling, responsiveness and overall polishing, and I'm really proud of the work I've done in this project.

Grin, Inc.
Grin is a platform that connects social media influencers and marketing teams, tracks their relationship and compensations, allowing those teams to move quickly and efficiently with their influencer marketing projects.

While working on this project, I touched several layers of the stack—from the back end with PHP and Laravel, setting up microservices and integrating them, to developing responsive components using Vue.js and Vuex. I'm proud of the work I did for Grin and happy that the solutions implemented accelerated the company's growth.

Visão Rio500

Platform designed to let the population of Rio de Janeiro express their dreams and desires, helping Rio's City Hall to develop the next fifty-year plan for the city.

Rio Media Center

Platform developed to help the international media get accreditation and overall support in their coverage of the Rio Olympic Summer Games of 2016.


PHP, JavaScript, TypeScript, HTML, CSS, HTML5, Python, Sass, PHP 7, GraphQL


Laravel 5, Material UI, Redux, AngularJS, Laravel, Django REST Framework, Django, Express.js, Next.js


React, Vue, jQuery, Redux-Saga, Emotion Library, Facebook API, Twitter API, Stripe API, Node.js, Formik, Playwright, SQLAlchemy


Gulp, Webpack, Git, PhpStorm, PyCharm, Grunt, Envoyer, Rollup, Terraform, Kibana, Sentry, Grafana, Yarn Workspaces, Keycloak, Notion, CircleCI, Tmux


Responsive Web Design (RWD), Agile Software Development, E2E Testing, Continuous Deployment, Continuous Integration (CI)


Front-end, Mobile Web, FastAPI, APIs, Forge, Apollo, Styled-components, User Experience (UX), User Interface (UI), Computer Science, Web Development, RTK Query, GitHub Actions, Monorepos, Neovim


Linux, Ubuntu, Firebase, Mobile, MacOS, Docker, Visual Studio Code (VS Code)


MySQL, Elasticsearch, PostgreSQL, PostGIS

2011 - 2011

Post-graduate Coursework in Web Development

Pontífice Universidade Católica do Rio de Janeiro - Rio de Janeiro

2005 - 2010

Bachelor's Degree in Computer Science

Federal University of Paraíba - Paraíba

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