Note: The job is a remote job and is open to candidates in USA. Topstep is an innovative company focused on building exceptional user experiences in mobile trading. As a Mobile Engineer III, you will play a foundational role in developing their mobile trading platform using React Native, contributing to the MVP launch and establishing engineering patterns for ongoing mobile development.
Responsibilities
- Contribute to the mobile MVP effort to establish our React Native application from the ground up, integrating with GraphQL APIs across our trader experience and trading experience platforms
- Establish engineering patterns for React Native development, including reusable components, custom hooks, TypeScript patterns, and testing strategies that other engineers can adopt
- Contribute to end-to-end mobile features from design through App Store and Play Store releases, ensuring seamless integration with backend services and optimal performance
- Partner with product and design to translate trader needs into mobile experiences that balance user experience with technical constraints and platform capabilities
- Contribute to mobile quality and performance by embedding testing, monitoring, crash reporting, and performance optimization into every feature you ship
- Embed within feature teams after MVP launch to drive ongoing mobile development, bringing mobile expertise to cross-functional squads
- Uphold React Native best practices, mobile-specific architectural thinking, and production ownership
- Champion mobile-first thinking across the organization, helping backend and frontend teams understand mobile constraints and opportunities
Skills
- 3 + years of professional experience building production mobile applications, with demonstrated impact in establishing patterns and practices that scaled across multiple teams
- Deep React Native expertise, including navigation (React Navigation), state management (Redux, Zustand, Context), native module integration, and performance optimization
- Strong TypeScript and modern JavaScript foundation with understanding of React patterns, hooks, component composition, and functional programming concepts
- Cross-platform mobile development experience shipping apps to both iOS App Store and Google Play Store, including an understanding of platform-specific differences and capabilities
- GraphQL client integration experience using Apollo Client or similar libraries, including cache management, optimistic updates, and error handling
- Strong database fundamentals, including experience with PostgreSQL or SQL Server-schema design, migrations, indexing, and query optimization
- Mobile-specific performance optimization, including understanding of bundle size, startup time, memory management, list virtualization, and image optimization
- Production mobile app experience, including crash reporting (Sentry, Crashlytics), analytics integration, remote config, and debugging production issues
- Testing mindset with experience writing unit tests (Jest), integration tests, and E2E tests (Detox, Appium) for React Native applications
- Understanding of mobile CI/CD, including automated builds, code signing, TestFlight/Play Store distribution, and release management
- Track record of technical leadership through architectural documentation, code reviews, component libraries, and establishing mobile engineering standards
- Excellent communication skills with the ability to explain mobile-specific constraints and trade-offs to varied audiences and build consensus across teams
- Comfortable making pragmatic decisions, balancing long-term mobile architecture with immediate feature delivery and MVP launch goals
- Experience building financial, trading, or fintech mobile applications where real-time data, reliability, and security are critical
- Background with native iOS (Swift/Objective-C) or Android (Kotlin/Java) development, and understanding when to drop down to native code
- Experience with real-time data integration using WebSockets or Server-Sent Events
- Familiarity with mobile authentication patterns (biometrics, OAuth, secure token storage)
- Experience with complex mobile UI patterns (charts, animations, gesture handling)
- Background building and maintaining shared component libraries or design systems for mobile
- Experience with Expo or similar React Native development platforms
- Understanding of mobile security best practices and secure coding for sensitive financial data
Benefits
- Topstep is an engaging working environment that ranges from fully remote to hybrid.
- Seven Company-paid Holidays and generous Family Leave.
- Paid time off is front-loaded.
- Competitive 401(k) matching, health, dental, and vision insurance are offered for full-time employees.
- Vacations are encouraged with a bonus for taking 5 consecutive days.
- Topstep offers a food and groceries budget and contributes towards health and wellness.
- Bonus: This position is eligible for a performance-based bonus as provided by the plan terms and governing documents.
Company Overview