Senior Fullstack Engineer, Frontend

Alt is unlocking the value of alternative assets, starting with the $5 B trading-card market. They are seeking a Senior Fullstack Engineer, Frontend with deep React Native expertise to own their flagship mobile experience and play a critical role in the architecture and performance of the app.

Responsibilities:

• Own Alt’s flagship mobile application our most important user-facing product
• Lead the React Native platform across build systems, deployments (store and OTA), CI/CD, performance, reliability, and developer experience
• Work across multiple product domains: Auctions, Search, Payments, Lending, Notifications, Authentication, Fixed Price Marketplace and more
• Build seamless, highly performant UIs that make a React Native app feel truly native
• Work with the native layers (iOS & Android), bridging JavaScript and native code where needed
• Partner closely with product, design, and business to influence what we build—not just how we build it
• Mentor, level up, and provide architectural guidance to other engineers
• Help us scale a global frontend/mobile team; grow into management over time if desired
• Contribute to backend systems as needed (Python/FastAPI/Postgres, 30% of role)

Requirements:

• 5-7 years of professional experience building production React Native apps at scale
• Experience shipping and maintaining ejected React Native applications
• Ability to work with native iOS/Android code (Kotlin, Java, Swift, and Objective C), JavaScript/TypeScript, and build high-quality bridges between them
• A strong product mindset: our engineers are highly product-focused and expected to have real influence
• Experience making React Native apps feel extremely polished, smooth, and native
• Motivation to tackle hard engineering challenges across performance, architecture, and mobile infrastructure
• Ability to work collaboratively in a fast-paced startup environment
• Background in fintech, marketplaces, gambling, hobby, or high-scale consumer mobile is a strong plus