Principal Mobile Software Engineer

About Upstart

At Upstart, we’re united by a mission that matters: to radically reduce the cost and complexity of borrowing for all Americans. Every day, we bring creativity, experimentation, and advanced AI to reshape access to credit, helping millions move forward financially with clarity and confidence.

As the leading AI lending marketplace, we partner with banks and credit unions to expand access to affordable credit through technology that’s both radically intelligent and deeply human. Our platform runs over one million predictions per borrower using more than 1,800 signals, powering smarter, fairer decisions for millions of customers. But the numbers only hint at the impact. Every idea, every voice, and every contribution moves us closer to a world where credit never stands between people and their financial progress.

We’re proudly digital-first, giving most Upstarters the flexibility to do their best work from wherever they thrive, alongside teammates across 80+ cities in the US and Canada. Digital-first doesn’t mean distant. We’re intentional about in-person connection through team onsites, planning sessions, and moments that spark creativity and trust. And whether you choose to work primarily from home or collaborate in-person from one of our offices in Columbus, Austin, the Bay Area, or New York City (opening Summer 2026), you’ll have the support to work in the way that works best for you.

If you’re energized by tackling meaningful problems, excited to innovate with purpose, and motivated by work that truly matters, we’d love to hear from you.

As a Principal Mobile Software Engineer at Upstart, you’ll sit at the intersection of mobile platform and product development. You’ll lead efforts to scale and refine our React Native architecture while partnering closely with product, design, and backend teams to ship impactful, high-quality features.

You’ll define technical direction, improve developer experience, and mentor other engineers — all while helping Upstart grow into a truly mobile-first company. This is a highly cross-functional role with visibility across the stack and deep influence on how we build and deliver mobile software. You’ll play a key role in shaping how mobile is built and scaled at Upstart — helping define mobile as a core product pillar and driving impact across teams and surfaces.

The Mobile team at Upstart is building the future of our user experience. Today, we have a live iOS app built in React Native, and we’re actively planning our Android expansion. Our platform is still early-stage, which means there's a huge opportunity to influence architecture, best practices, performance, and product velocity.

We move quickly, collaborate tightly with backend and design, and care deeply about quality — not just in the UI, but in the systems that power a great user experience.

• Drive technical strategy for our mobile apps — from platform architecture to product scalability and developer experience.
• Build foundational systems in React Native that enable fast, high-quality feature development across both iOS and Android.
• Collaborate with product and design to scope, implement, and launch user-facing features that align with company goals.
• Bridge mobile and backend systems by shaping APIs and improving client-server interaction patterns.
• Identify friction in the mobile development lifecycle and lead improvements to tooling, modularization, CI, and testing strategies.
• Mentor engineers and help grow a culture of ownership, technical rigor, and continuous learning.
• Influence both product and platform direction as we scale our mobile efforts across multiple surfaces and teams.
• Support company goals such as improving user engagement, increasing retention, and unlocking new growth channels through mobile innovation.
• Help define and uphold the engineering culture, patterns, and practices that guide mobile development at Upstart.

• Have 8+ years of professional software development experience, including meaningful contributions to production mobile apps.
• Have built and maintained features in both React Native and at least one native…