João
From Brazil (UTC-3)
Lemon.io stats
2
projects done1171
hours workedJoão – React Native, Next.js, React
João is an experienced Front-End and Mobile Developer with a strong background in React, React Native, Next.js, and TypeScript, delivering high-quality applications for industries including e-commerce, fintech, agritech, and education. Skilled in developing scalable front-end architectures, microfrontends, and cross-platform mobile solutions for both Android and iOS, he also excels in consulting and architectural decisions. Passionate about building impactful, user-centered products, he combines strong technical expertise with collaborative leadership to deliver reliable, maintainable, and elegant solutions across platforms.
10 years of commercial experience in
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Let’s get started today!Experience Highlights
Senior Front-End developer
I worked as a Senior Frontend Developer staffed by Compass UOL at the Livelo client, focused on React, React Native and Next.js.
TypeScript, React, React Native, Next.js, microfrontends, 2FA, MFA, design system, Keychain, Swift, Kotlin, Objective-C, Java, iOS, Android.
- implemented and evolved Livelo's design system on web and mobile.
- built on my own the second-factor authentication (2FA) microfrontend: on the web, a Next.js microfrontend; on mobile, the equivalent flow in React Native.
- implemented native Keychain integration in Objective-C on iOS and Java on Android, then migrated that library to Swift and Kotlin.
- shipped TypeScript product features across the loyalty program's apps and web, working with the client squad.
Senior Mobile Developer
I worked as a Senior React Native Developer at a US consultancy, allocated to The Good Game (thegoodgame.com), a youth-sports and coaching marketplace. I took part in the full cycle from MVP and beta to launch, then kept evolving the main mobile app and the web admin.
Technologies: React Native, TypeScript, React, JavaScript, GraphQL, Context API, Redux Thunk, React Navigation, Firebase App Distribution, Plaid, iOS, Android, Git, Agile, Scrum.
- I built and maintained React Native features for iOS and Android, from MVP to store launch, on a coaching marketplace.
- I shipped a GraphQL typing-generation pipeline between front and back and a build/test/deploy loop with Firebase App Distribution (iOS and Android), in the same spirit as Integra.
- I integrated the Plaid SDK for US open banking.
- I contributed to the web admin, architecture, code review, quality bars, beta testing and maintenance.
Senior Front-End Consultant
I worked as a Consultant Front-End Developer at Avanade, on two enterprise accounts: Bank J. Safra Sarasin (Wealth app, Swiss private banking) and Seara (Integra app, Brazilian agribusiness, JBS group). The project is in the agribusiness sector, and its primary objective is to create a comprehensive digital platform to streamline and enhance the various processes within the agribusiness ecosystem.
- React Native app (no Expo) for integrated poultry and swine producers (farm, batches, documents, invoices). Offline with WatermelonDB. GraphQL in the app, with a typing-generation pipeline that sped up development and integration with the Java backend (I only touched Java in small ways).
- I owned 100% of CI/CD. I replaced manual deploy with Fastlane and sped up final tests with the client, QA and PM via Firebase App Distribution (Android and iOS).
- I cut bug-response time by 80% and initial load from 4 to 8 minutes down to 45 s on a bad network and 0.8 s on a good network.
Senior Front-End Consultant
This project involved creating a digital trading platform for a client in the Swiss banking sector. The platform included a QR code payment system, online trading capabilities, asset management, and a watchlist feature for monitoring specific stocks and financial instruments.
- Launched the product on both Android and iOS;
- Was responsible for the development of some features like the watchlist and QR code payments;
- Redesigned all search fields to perform better with debounce;
- Refactored code to achieve better performance;
Main achievement: The project has successfully met its objectives and demonstrated the potential of digital technology. The feedback received from the initial group of users was highly positive and highlighted the potential of digital technology to revolutionize the banking and trading experience.
Front-End Developer
The project is a single tool with end-to-end integration, enabling real-time communication, organization, management, and data security for schools.
- Implemented advanced full-text search;
- Worked on the development of the two main products, using internal tools and CI/CD automation;
- Created a text formatting library for React Native internally;
- Wrote unit, integration, and e2e tests;
- Participated in technical leadership training and joined study groups on microservices and design systems.
Minute of Glory: Presented internal lectures on "React Native Architecture and State (2021)" and maintained internal component libraries for web and mobile.
Lead Full-Stack Developer
The project was an internal Edtech application allowing public school classes to continue functioning remotely during the pandemic.
- Created front-end and back-end architecture;
- Participated in planning and workflow definitions;
- Developed CI/CD automation and on-premise solutions;
- Built front-end components library;
- Wrote unit, integration, and e2e tests;
- Integrated with different providers.
Main achievement: Impacted almost 200k students from Piaui public schools through home education during the COVID-19 pandemic.