Senior Mobile Software Engineer, Cash Line

The Role

As a Senior Mobile Software Engineer on Upstart’s Cash Line team, you’ll build mobile experiences for a new consumer credit product that gives customers always-on access to a reusable line of credit they can draw from, repay, and use again in real time. You’ll use React Native to ship high-quality features that directly shape how customers discover, access, and manage Cash Line in the mobile app.

This is a hands-on role for an engineer who wants to own end-to-end feature delivery, make strong technical decisions, and help define the mobile experience for a foundational new business line at Upstart. You’ll work closely with product, design, backend, and cross-functional partners to build thoughtful, reliable experiences in a space where speed, correctness, and customer trust all matter.

The Team

The Cash Line team is building one of Upstart’s newest consumer products: a revolving credit experience designed to create a more durable, recurring relationship with customers beyond a one-time loan. As part of that work, the team is shaping the mobile experience for a product with broad visibility across the customer journey, from application and approval through ongoing account access and reuse.

We’re a fast-moving, highly cross-functional team working at the intersection of consumer product, real-time systems, and financial infrastructure. Our engineers partner closely with teams across product, growth, finance, compliance, and capital markets, and we value people who can combine strong product instincts with pragmatic execution in an ambiguous, high-impact environment.

What You’ll Do

• 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.

We’re Excited About You Because You…

• 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.

Bonus Points If You…

• 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.

Position Location - This role is available in the following locations: Remote, San Mateo, Columbus, Austin 

Time Zone Requirements - This team operates across all U.S. time zones.

Travel Requirements - This team has regular on-site collaboration sessions. These occur 3 days per quarter at an Upstart office. If you need to travel to make these meetups, Upstart will cover all travel related expenses.

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