João Guilherme Fonseca

- Architected and built the company's mobile app from scratch using Expo and React Native, making key architecture decisions from day one.

- Drove feature development across the full product lifecycle, coordinating closely with cross-functional teams.

- Applied TypeScript throughout for type safety, maintainability, and scalability.

- Developed and scaled React Native / Expo apps, refactoring legacy code and shipping new features with a focus on performance and UX.

- Led state management migration from Redux to Zustand, adopting a leaner, more modern approach that reduced boilerplate and improved maintainability.

- Maintained high coding standards through peer code reviews and consistent TypeScript usage.

- Built a real-time operations dashboard in React.js and TanStack Table for internal teams to monitor deliveries end to end, including request status, driver acceptance, SLA timing, and operational issues.

- Implemented live delivery-status updates via Websockets with Pusher, allowing employees to track changes instantly without manual refresh.

- Worked on a delivery flow where clients requested deliveries through the app and drivers accepted jobs on mobile, ensuring the dashboard accurately reflected each stage of the operation in real time.

- Led the full migration of a legacy Angular application to a modern React + TypeScript + Tailwind CSS stack, improving performance and developer experience.

- Built and refined responsive React + TypeScript interfaces during the migration, improving usability and maintainability across internal workflows.

- Optimized applications for speed, maintainability, and responsive design across devices.

- Developed REST APIs with Node.js and Express; integrated databases with Prisma ORM.

- Prototyped a real-time chat feature using Socket.io — directly relevant to Websocket-based communication.

- Wrote automated tests with Jest, reinforcing a culture of quality and testing best practices.

- Built a .NET API for a virtual reality research project; developed UI prototypes in Unity with C#.

I joined a virtual reality project where I learned Unity with C#. I focused on UI prototyping and gained hands-on experience in game development and UX design.