[Remote] Senior Mobile Engineer

Note: The job is a remote job and is open to candidates in USA. Topstep is a company focused on building exceptional user experiences through innovative technology. As a Senior Mobile Engineer, you will play a key role in developing the mobile trading platform using React Native, establishing architecture patterns, and mentoring other engineers while driving ongoing mobile development.ResponsibilitiesLead 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 platformsEstablish engineering patterns for React Native development, including reusable components, custom hooks, TypeScript patterns, and testing strategies that other engineers can adoptOwn end-to-end mobile features from design through App Store and Play Store releases, ensuring seamless integration with backend services and optimal performancePartner with product and design to translate trader needs into mobile experiences that balance user experience with technical constraints and platform capabilitiesDrive mobile quality and performance by embedding testing, monitoring, crash reporting, and performance optimization into every feature you shipEmbed within feature teams after MVP launch to drive ongoing mobile development, bringing mobile expertise to cross-functional squadsMentor engineers on React Native best practices, mobile-specific architectural thinking, and production ownershipChampion mobile-first thinking across the organization, helping backend and frontend teams understand mobile constraints and opportunitiesSkills5+ years of professional experience building production mobile applications, with demonstrated impact in establishing patterns and practices that scaled across multiple teamsDeep React Native expertise, including navigation (React Navigation), state management (Redux, Zustand, Context), native module integration, and performance optimizationStrong TypeScript and modern JavaScript foundation with understanding of React patterns, hooks, component composition, and functional programming conceptsCross-platform mobile development experience shipping apps to both iOS App Store and Google Play Store, including an understanding of platform-specific differences and capabilitiesGraphQL client integration experience using Apollo Client or similar libraries, including cache management, optimistic updates, and error handlingMobile-specific performance optimization, including understanding of bundle size, startup time, memory management, list virtualization, and image optimizationProduction mobile app experience, including crash reporting (Sentry, Crashlytics), analytics integration, remote config, and debugging production issuesTesting mindset with experience writing unit tests (Jest), integration tests, and E2E tests (Detox, Appium) for React Native applicationsUnderstanding of mobile CI/CD, including automated builds, code signing, TestFlight/Play Store distribution, and release managementTrack record of technical leadership through architectural documentation, code reviews, component libraries, and establishing mobile engineering standardsExcellent communication skills with the ability to explain mobile-specific constraints and trade-offs to varied audiences and build consensus across teamsComfortable making pragmatic decisions, balancing long-term mobile architecture with immediate feature delivery and MVP launch goalsExperience building financial, trading, or fintech mobile applications where real-time data, reliability, and security are criticalBackground with native iOS (Swift/Objective-C) or Android (Kotlin/Java) development, and understanding when to drop down to native codeExperience with real-time data integration using WebSockets or Server-Sent EventsFamiliarity 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 mobileExperience with Expo or similar React Native development platformsUnderstanding of mobile security best practices and secure coding for sensitive financial dataBenefitsTopstep is an engaging working environment that ranges from fully remote to hybrid.We foster a culture of collaboration by keeping cameras on during meetings and maintaining a robust Slack environment for communication.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 OverviewTopstep is a financial organization that enables resource traders to develop and learn in the trading industry. It was founded in 2012, and is headquartered in Chicago, Illinois, USA, with a workforce of 201-500 employees. Its website is https://www.topstep.com.