Staff Software Engineer, Mobile (App Infrastructure)

About the role

At Affirm, we exist for the moments that matter—giving people a clear, predictable way to pay over time, with no hidden fees, no surprises, and no tradeoffs on what matters most. App Infrastructure is the team behind Affirm's shared mobile app infrastructure — the platform every other mobile feature team builds on. We own the app’s shared components: design system, networking, observability, experimentation, CI/CD, app releases, developer tooling, availability/stability, and more. We care about ownership: shipping tools and runbooks other teams actually adopt, writing specs before building, and being the go‑to experts for the mobile tech stack. We're small, technical, and highly collaborative.

Responsibilities

• Set technical strategy for the team on a year‑long time scale and help tie it together with critical, business‑impacting projects.
• Collaborate across product management, design & analytics to ensure technical sustainability, risks and trade‑offs are understood and managed.
• Act as a force‑multiplier by defining and advocating technical solutions and operational processes.
• Own team operations and availability: ensure monitoring, triage rotations, playbooks, policies, testing and alerting are in place to support “keep the lights on” and on‑call efforts.
• Foster a culture of quality and ownership by setting code review and design standards, advocating them beyond the team via writing and tech talks.
• Help develop talent by providing feedback and guidance, leading by example.

Requirements

• 7+ years of experience developing and architecting mobile applications; 4+ years using React Native.
• Proficient in JavaScript/TypeScript.
• Hands‑on experience with React Native and Expo, including authoring or migrating native modules and components.
• Experience with complex state management in React apps; proficiency with Redux Toolkit is a bonus.
• Performed React Native SDK major updates and can debug across the JS↔native boundary under the New Architecture.
• Stay up‑to‑date on native OS releases and anticipate their impact on React Native apps.
• Experience with mobile testing and observability tooling — E2E frameworks like Maestro/Appium, crash reporting Sentry/Crashlytics, experimentation/feature‑flagging platforms like Statsig/LaunchDarkly — and enjoy building tooling other teams adopt.
• Proficient and up‑to‑date on AI‑assisted development (e.g., Claude Code or comparable agentic tooling) and able to apply judgment about where agents help, where they need guardrails, and how to keep the quality bar high.
• Proven track record of driving a team to execute large projects; experience delivering major features, system components, or deprecating existing functionality via technical and execution plans.
• Write high‑quality code that is easily understood and used by others.
• Comfortable moving from low