Senior Mobile Software Engineer

Upstart•San Mateo, CA

1d•Remote

About The Position

Upstart is the leading AI lending marketplace partnering with banks and credit unions to expand access to affordable credit. By leveraging Upstart's AI marketplace, Upstart-powered banks and credit unions can have higher approval rates and lower loss rates across races, ages, and genders, while simultaneously delivering the exceptional digital-first lending experience their customers demand. More than 80% of borrowers are approved instantly, with zero documentation to upload. Upstart is a digital-first company, which means that most Upstarters live and work anywhere in the United States. However, we also have offices in San Mateo, California; Columbus, Ohio; Austin, Texas; and New York City, NY (opening Summer 2026). Most Upstarters join us because they connect with our mission of enabling access to effortless credit based on true risk. If you are energized by the impact you can make at Upstart, we’d love to hear from you! As a Senior Mobile Software Engineer at Upstart, you’ll help design and build scalable, high-quality mobile applications using React Native. You’ll collaborate closely with product managers, designers, and backend engineers to deliver features that delight users and align with company goals. This is a hands-on, execution-focused role for an experienced engineer who wants to ship features, own technical decisions, and improve our mobile platform. You’ll contribute to engineering quality through thoughtful system design, code review, and a focus on long-term maintainability. The Mobile team at Upstart is building the future of our user experience. Our mobile codebase is React Native-first, and we’re in the early stages of expanding from iOS into Android. Our work spans user-facing features, performance optimization, platform tooling, and tight collaboration with backend and design partners. We’re a fast-moving team that values pragmatism, quality, and impact — and we’re laying the foundation for a scalable and user-first mobile platform.

Requirements

Have 6+ years of professional software development experience, including meaningful contributions to production mobile apps.
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.

Nice To Haves

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.

Responsibilities

Build and maintain user-facing features in our React Native mobile apps across iOS (and Android, as we expand).
Design and implement mobile components and subsystems that are performant, maintainable, and scalable across platforms.
Collaborate with product and design teams to scope, implement, and launch features that align with user and business needs.
Contribute to platform improvements, including tooling, testing strategies, CI/CD, and performance monitoring.
Work with backend engineers to define mobile-specific APIs and improve client-server integration patterns.
Identify and resolve performance or reliability issues in the mobile experience.
Participate in code reviews, architecture discussions, and technical planning to raise engineering quality across the team.
Support a strong mobile engineering culture through mentorship, collaboration, and a focus on continuous improvement.

Benefits

Competitive Compensation (base + bonus & equity)
Comprehensive medical, dental, and vision coverage with Health Savings Account contributions from Upstart
401(k) with 100% company match up to $4,500 and immediate vesting and after-tax savings
Employee Stock Purchase Plan (ESPP)
Life and disability insurance
Generous holiday, vacation, sick and safety leave
Supportive parental, family care, and military leave programs
Annual wellness, technology & ergonomic reimbursement programs
Social activities including team events and onsites, all-company updates, employee resource groups (ERGs), and other interest groups such as book clubs, fitness, investing, and volunteering
Catered lunches + snacks & drinks when working in offices