Staff Software Engineer - Mobile, App Infrastructure

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.

What You'll Do

• You will be responsible for setting technical strategy for your team on a year-long time scale, and help your team tie it together with critical, business-impacting projects.
• You will collaborate across teams in the product development lifecycle by collaborating with product management, design & analytics to ensure technical sustainability, risks and trade-offs are well understood and managed.
• You will act as a force-multiplier for your team through your definition and advocacy of technical solutions and operational processes.
• You take ownership of your team’s operations and availability by ensuring you have the right monitoring, triage rotations, playbooks, policies, testing and alerting in place to support “keep the lights on” & on-call efforts.
• You will foster a culture of quality and ownership on your team by setting code review and design standards for your team, and advocating for them beyond your team through your writing and tech talks.
• You will help develop talent on your team by providing feedback and guidance, and leading by example.

What We Look For

• You have 7+ years of experience of developing and architecting mobile applications; 4+ using React Native
• You are proficient in working with Javascript/Typescript.
• You have hands-on experience with React Native and Expo, and have authored or migrated native modules and components.
• You have experience with complex state management in a React app. Proficiency with Redux Toolkit is bonus
• You have performed React Native SDK major updates, and you can debug across the JS↔native boundary under the New Architecture.
• You stay up-to-date on native OS releases and can anticipate how they land in a React Native app
• You have experience with mobile testing and observability tooling — E2E frameworks like Maestro/Appium, crash reporting Sentry/Crashlytics, and experimentation/feature-flagging platforms like Statsig/LaunchDarkly — and enjoy building tooling other teams actually adopt.
• You are proficient and up to date on AI-assisted development — Claude Code or comparable agentic tooling — and apply judgment about where agents help, where they need guardrails, and how to keep the quality bar high.
• You have a proven track record of driving a team to execute large projects
• You have experience delivering major features, system components or deprecating existing functionality in a system through the definition of a technical and execution plan. You write high quality code that is easily understood and used by others.
• You thrive in ambiguity, and are comfortable moving from low level language idioms all the way to the architecture of large systems to understand how they work.
• Your growth and impact trajectory demonstrates that you have mastered gathering and iterating on feedback from your engineering and cross-functional peers.
• You have strong verbal and written communication skills that support effective collaboration with our global engineering team.
• This position requires either equivalent practical experience or a Bachelor’s degree in a related field.