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FinTech · SaaSOngoingOpen Source Contributor · Guest Engineer
New Expensify
Chat-Based Financial Collaboration
Contributed to Expensify's production React Native platform used by millions for expense management and team collaboration — recognized with a Guest Engineer invitation to Curaçao.
Millions
Users on platform
Guest
Engineer recognition
OSS
Production contributions
Global
Team collaboration
React NativeTypeScriptGraphQLReal-time ChatOpen Source
Product Preview
The Challenge
Building a real-time financial product at massive scale
- —Expensify needed a mobile experience that matched the complexity of their web platform — chat-based expense reporting, receipt scanning, and team workflows.
- —The codebase serves millions of users with strict performance, accessibility, and reliability requirements.
- —Contributions required deep understanding of production React Native patterns at enterprise scale.
Product Goals
- ✓Ship high-quality features to a production codebase with rigorous review standards
- ✓Maintain performance across iOS and Android under real user load
- ✓Collaborate with a distributed engineering team across time zones
The Solution
Production-grade contributions to a world-class RN codebase
- —Delivered features and fixes within Expensify's open-source contribution workflow
- —Followed strict TypeScript, testing, and code review standards used by the core team
- —Worked within a chat-first UX paradigm requiring real-time state synchronization
Architecture
- ✓React Native with TypeScript strict mode
- ✓GraphQL API layer with optimistic updates
- ✓Modular feature-based architecture with shared design system
- ✓CI/CD with automated testing before merge
Technical Highlights
How It Was Built
React Native & TypeScript
Real-time chat & notifications
GraphQL data layer
Performance profiling
Open-source contribution workflow
Cross-platform UI consistency
Lessons Learned
- →Enterprise React Native requires discipline in architecture, testing, and review culture
- →Open-source contribution at scale teaches patterns that transfer directly to client work
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