Goodword
Staff Mobile & AI Platform Engineer
- My contribution
- Owned product-to-store delivery for a React Native, Expo, and TypeScript app; built C++ Nitro Modules and integrated on-device and retrieval-backed mobile features.
Staff Mobile Engineer · React Native · Applied AIRemote · Brazil · US & Europe overlap
João Paulo Costa Marra
Mobile platforms and applied AI systems, from architecture through delivery.
- React Native · Expo · TypeScript
- Applied AI · Agent systems
- Remote from Brazil · US and Europe overlap
I’m a Staff Mobile Engineer focused on React Native, Expo, and TypeScript. I build and modernize iOS and Android products, from architecture and API integration through testing, native performance, and store releases. Across 16+ years in software engineering, I’ve led mobile modernizations and shared-platform work. My applied-AI experience includes on-device and retrieval-backed mobile features. In independent projects, I’ve built typed agent decision APIs with evaluation checks, worked on tool-call scheduling and failure recovery, and implemented MCP services in TypeScript, Go, and Rust.
Remote availabilityBased in Joinville, Brazil (UTC−3) · US and European time-zone overlap
Selected products
Live on the store
Open to new roles· Staff Mobile · Mobile Platform · Applied AI
01 / Selected work
Mobile platforms, native systems, and applied AI.
Selected engineering work and leadership, including independent agent-tooling projects.
- Selected proof6engineers on mobile modernization
- Legacy React Native to Expo
- C++Nitro Modules
- Authentication, secure storage, markdown
- Firstbare React Native app
- UnitedHealth Group business unit
- 26frontend developers led
- Healthcare workflow modernization
- Agentdecision APIs and MCP
- Evaluation checks, scheduling, recovery
- 16+years in software engineering
- Mobile and web products
02 / Work
React Native products live on the App Store and Play Store.
Each role is paired with the App Store product or live website it helped move forward.
Post Op
Staff Mobile Architect
- My contribution
- Led a six-engineer legacy-to-Expo modernization for a production React Native app, setting architecture, review, and release practices.
Gopuff
Senior Frontend Developer
- My contribution
- Owned shared React Native and React Native Web components, diagnostics, automated testing, CI/CD, and local-first web foundations.
Medify Ltd
Senior Frontend Developer
- My contribution
- Delivered React and TypeScript healthcare interfaces for web and desktop, plus C++-backed content workflows and monorepo quality improvements.
Znipe Esports
Senior Frontend Engineer
- My contribution
- Modernized a legacy jQuery esports-streaming platform with React and TypeScript and built React Native and Next.js experiences.
Triggy
Lead Mobile Engineer
- My contribution
- Led an Expo-to-React Native re-architecture for international sports-data products and coordinated TypeScript migration and testing.
OLX Group
Senior Frontend Engineer
- My contribution
- Delivered dubizzle.com property workflows with React and IndexedDB, and helped extend legacy frontend delivery into React Native.
Case studies & guides
How I approach mobile engineering.
A project account, a look inside a public native module, and a guide for teams making their first mobile hire.
English
Modernizing a healthcare app with Expo
My role at Post Op and the decisions that matter in an Expo migration.
Read articleEnglish
React Native markdown performance with Nitro
Where parsing runs, what native code changes, and how to benchmark it.
Read articleEnglish
Hiring your first React Native engineer
Architecture, delivery, and ownership questions to settle before the first release.
Read article03 / Expertise
Mobile platforms, native modules, and agent systems.
From product architecture to native integration and evaluated AI tooling.
Stage01Product surface
Mobile foundations
Cross-platform architecture and delivery for reliable iOS and Android products.
- React Native
- Expo
- TypeScript
- New Architecture
- Fabric
- iOS
- Android
Stage02Native runtime
Native integration
Native modules and on-device AI integration for mobile product workloads.
- C++
- JSI
- Nitro Modules
- Swift
- Kotlin
- Native modules
- On-device AI
- Retrieval-backed features
Stage03Agent systems
Applied AI and agent systems
Independent agent tooling built with typed APIs, evaluation checks, recovery, and MCP services.
- Model API integration
- Typed decision APIs
- Golden-case evaluation
- Tool-call scheduling
- Failure recovery
- MCP services
- TypeScript
- Go
- Rust
Open source · 02 repositories highlighted
Production problems, solved in the open.
Focused tools for React Native performance and developer workflow — small enough to understand, useful enough to ship.
01 / 02
react-native-nitro-markdown
C++ Nitro Module for markdown parsing off the JS thread — built for LLM and chat UIs.
View repository02 / 02
inline-blame-mini
Lightweight inline git blame tooling.
View repository04 / Experience
16+ years building and leading mobile delivery.
A concise record of hands-on ownership in lean teams and larger organizations, across architecture, implementation, and release delivery.
Goodword
Staff Mobile & AI Platform Engineer
Owned product-to-store delivery for a React Native, Expo, and TypeScript app on iOS and Android: architecture, APIs, implementation, testing, observability, EAS builds, OTA updates, and store releases.
Scope and technical context
- Built C++ Nitro Modules for authentication, secure storage, and markdown on JSI and the New Architecture.
- Integrated on-device AI and retrieval-backed mobile features at the product/API layer, while leading a four-engineer product team and contributing to implementation and code review.
- React Native
- Expo
- TypeScript
- New Architecture
- Nitro Modules
- C++
- On-device AI
- EAS
- OTA
- Sentry
Post Op
Staff Mobile Architect
Led a six-engineer team through a legacy-to-Expo modernization for a production React Native and TypeScript app on iOS and Android.
Scope and technical context
- Set mobile architecture standards, review practices, and release workflows while owning implementation, API integration, and testing.
- Translated product and design requirements into shipped features across personalization, rendering performance, and mobile UX, including local-first client data with TanStack DB.
- React Native
- Expo
- TypeScript
- EAS
- Mobile architecture
- Native bridges
- API integration
- E2E testing
Gopuff
Senior Frontend Developer
Owned the shared React Native and React Native Web component library in TypeScript for commerce and logistics products.
Scope and technical context
- Worked in a four-engineer library team on reusable interfaces, diagnostics, automated testing, and CI/CD to support consistent delivery across web and mobile surfaces.
- Built React and Next.js foundations, including local-first client persistence with IndexedDB.
- React Native
- React Native Web
- React
- Next.js
- TypeScript
- Component libraries
- Design systems
- Cypress
- CI/CD
Medify Ltd
Senior Frontend Developer
Delivered React and TypeScript web and desktop healthcare interfaces within a 12-engineer delivery initiative.
Scope and technical context
- Built a C++-backed content management workflow so non-technical teams could maintain healthcare content.
- Improved monorepo organization, CI/CD, and automated testing for healthcare product delivery.
- React
- TypeScript
- C++
- Monorepo
- CI/CD
- Healthcare technology
- TDD
- Automated testing
Znipe Esports
Senior Frontend Engineer
Modernized a legacy jQuery esports streaming platform with React and TypeScript, and built React Native mobile and Next.js web experiences.
Scope and technical context
- Introduced Jest, Cypress, and test-driven development practices to support changes to critical product flows.
- React Native
- Next.js
- React
- TypeScript
- JavaScript
- Jest
- Cypress
- TDD
Triggy
Lead Mobile Engineer
Led re-architecture of a legacy Expo sports-data app into a React Native and TypeScript platform for international client products.
Scope and technical context
- Drove TypeScript migration, unit and end-to-end testing, and coordination of mobile releases with product and engineering stakeholders.
- React Native
- Expo
- TypeScript
- Mobile architecture
- TDD
- E2E testing
- International product delivery
OLX Group
Senior Frontend Engineer
Delivered property marketplace workflows for dubizzle.com with React web interfaces and local-first client persistence through IndexedDB.
Scope and technical context
- Helped modernize legacy frontend architecture and extend product delivery into React Native, with automated tests for listing and property flows.
- React Native
- React
- JavaScript
- Node.js
- Frontend architecture
- Marketplace platforms
- Test automation
- TDD
UnitedHealth Group
Lead Software Engineer
Led 26 frontend developers through modernization of healthcare workflows from jQuery and Bootstrap to React and an internal component system.
Scope and technical context
- Defined migration architecture, reusable component patterns, review standards, and delivery sequencing for incremental adoption.
- Built the business unit's first bare React Native mobile app and defined its initial mobile architecture.
- React
- React Native
- JavaScript
- Frontend architecture
- Healthcare technology
- Component systems
- Technical leadership
Multiple Companies
Independent Software Consultant - Fullstack Engineering
Delivered client products using JavaScript, Node.js, PHP, Laravel, CMS platforms, REST APIs, SQL, and MongoDB across healthcare, e-commerce, and business operations.
Scope and technical context
- Owned discovery, architecture, implementation, integrations, testing, and releases, translating client requirements into maintainable web and backend systems.
- JavaScript
- Node.js
- PHP
- Laravel
- Magento
- WordPress
- SQL
- MongoDB
- REST APIs
05 / Questions
Remote Staff React Native, answered.
What recruiters and founders ask before the first call.
- Are you open to remote Staff Mobile or Applied AI roles?
- Yes. I’m based in Joinville, Brazil, and I’m interested in Staff Mobile, Mobile Platform, and product-focused Applied AI Engineer roles.
- Which time zones do you overlap with from Brazil?
- I’m based in Brazil (UTC−3) and coordinate with teams in US and European time zones.
- What does “first mobile hire” mean in practice?
- As a first mobile hire, I can establish React Native and Expo foundations, architecture, API integration, testing, EAS builds, OTA updates, observability, and the first App Store and Play Store releases, then help a lean team maintain the platform.
- What is your core stack?
- React Native, Expo, and TypeScript, with C++ Nitro Modules and native Swift or Kotlin when needed. My applied-AI work includes on-device and retrieval-backed mobile features, plus independent agent APIs, evaluation checks, tool-call recovery, and MCP services.