Senior Mobile Software Engineer, Cash Line

Upstart is a leading AI lending marketplace focused on reducing the cost and complexity of borrowing. As a Senior Mobile Software Engineer, you will build mobile experiences for a new consumer credit product, working with cross-functional teams to deliver high-quality features in React Native.

Responsibilities:

• Build and ship user-facing mobile features for Cash Line in React Native across iOS and Android as the product expands
• Design mobile components and systems that are scalable, maintainable, and reliable for a product that operates in real time and directly affects customers’ access to credit
• Partner closely with product, design, and backend engineers to scope, build, and launch experiences that balance customer needs, business goals, and technical quality
• Help define the mobile experience for a foundational new business line, contributing both to near-term feature delivery and longer-term platform direction
• Improve mobile developer velocity and product quality through better tooling, testing approaches, release practices, observability, and performance monitoring
• Work with backend partners to shape APIs and integration patterns that create smooth, resilient client-server experiences
• Identify and resolve performance, usability, and reliability issues in the mobile product, with a strong focus on long-term maintainability
• Contribute to engineering quality through code review, system design discussions, technical planning, and mentorship across the team

Requirements:

• Bachelor's degree in Computer Science, Engineering, or Mathematics, or a related field (or its equivalent) + 4 years of experience
• Have experience building in React Native, and familiarity with at least one native platform (e.g., Swift/Objective-C for iOS or Kotlin/Java for Android)
• Understand mobile performance, memory management, and platform-specific constraints
• Communicate effectively with cross-functional partners in product, design, and backend engineering
• Take ownership of your work and are comfortable delivering complex features from planning through release
• Balance speed and quality, and advocate for maintainable, scalable engineering solutions
• Contribute to team culture and engineering practices through feedback, mentoring, and collaboration
• Embrace a growth mindset and enjoy learning from others while helping teammates grow
• Have helped launch or scale a React Native app on the Android platform
• Are comfortable working with TypeScript or custom native modules
• Have experience with mobile analytics, push notifications, deep linking, or A/B testing frameworks
• Have worked in a fast-paced product company where mobile was a primary user touchpoint
• Have contributed to internal tools, processes, or systems that improved mobile developer velocity or code quality