Principal Mobile Software Engineer

About Upstart

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; and Austin, Texas.

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 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 platform (e.g., Swift/Objective‑C for iOS or Kotlin/Java for Android).
• Understand the nuances of mobile performance, memory management, and platform‑specific challenges.
• Have led architecture planning and helped engineering teams make informed tradeoffs.
• Communicate early and often with cross‑functional partners in product, design, backend, and QA to ensure alignment and shared understanding.
• Take ownership of your work from design through delivery, and value long‑term thinking over quick fixes.
• Appreciate the strength of diverse perspectives and thrive on being part of an inclusive, collaborative team.
• Embrace a growth mindset, value mentorship, and enjoy helping…