Staff Software Engineer (iOS/Swift & React Native)

Linus Health is a Boston-based digital health company transforming brain health worldwide. We combine cutting-edge neuroscience, clinical expertise, and AI to advance early detection and intervention for cognitive and brain disorders—empowering people to live longer, healthier lives. With 100+ team members and growing, we’re entering a phase of accelerated growth and looking for top talent to help shape our future.

The Role:

We’re looking for a Staff Software Engineer to lead our mobile apps across iOS (Swift) and React Native. You’ll set technical direction, design and build reusable component libraries, and raise the bar on quality, performance, and accessibility. You’ll also champion AI-assisted engineering—both to accelerate development (e.g., code generation, testing, refactors, documentation) and to integrate AI-powered visualizations that help clinicians and patients make sense of complex brain-health data. This role is highly cross-functional and pivotal to our mission. 

What You’ll Do:

• Own the mobile architecture across iOS (Swift/SwiftUI/UIKit) and React Native—modularity, performance, security, and observability
• Create and maintain reusable mobile component libraries (design-system alignment, theming, accessibility, localization, dark mode)
• Ship AI-enabled features that surface insights visually (charts/plots/progressions) and responsibly—privacy-by-design, auditable outputs
• Raise engineering standards: testing (unit/snapshot/e2e), CI/CD for mobile, OTA strategies, release automation, crash analytics, and telemetry
• Mentor and unblock engineers; drive clear design docs, ADRs, and code reviews; partner deeply with Product, Design, Data Science/Medical, and Security
• Lead cross-team initiatives (performance, reliability, offline/edge patterns, network/data sync, app startup time, bundle size reduction)
• Champion AI-assisted workflows to boost delivery speed and quality (intentional prompts, verification practices, secure usage guidelines)
• Collaborate with Data Science/Medical to integrate model outputs safely and clearly into the UI, including uncertainty and context visualization

About You:

Must Have’s:

• 10+ years of software engineering experience with significant time in mobile; 5+ years building and shipping iOS apps in Swift; 3+ years with React Native at scale.
• Expert in Swift/SwiftUI (and/or UIKit), Xcode tooling, Instruments, and Apple platform fundamentals (background tasks, permissions, Keychain, App Store Connect, TestFlight).
• Strong React Native fundamentals (bridge/native modules, performance profiling, Hermes, Metro/bundling, OTA, navigation).
• Proven track record designing reusable component systems (design tokens, accessibility, theming, API ergonomics, documentation).
• Hands-on experience using AI to accelerate coding (scaffold code/tests, refactors, docs) and productizing AI in-app (safe prompts, evaluation, guardrails).
• Depth in mobile data flows (REST/gRPC, GraphQL, streaming), offline-first sync, error handling, and app state management.
• Quality mindset: unit/UI/e2e testing (XCTest, snapshot testing, Detox), monitoring, crash analytics, metrics/SLOs.
• Security and privacy literacy suitable for healthcare contexts (e.g., PII/PHI handling patterns, least-privilege, secure storage).
• Clear technical communication: design docs, ADRs, tradeoff analysis, and stakeholder alignments

Nice To Have’s:

• Experience in digital health or clinical workflows; familiarity with regulated environments
• Data visualization skills (e.g., Charts on iOS, D3/Reanimated/Skia in RN) and communicating uncertainty
• Native Android familiarity (Kotlin) or cross-platform build/release expertise
• Prior ownership of design systems or component libraries used across multiple apps/teams
• Experience with on-device ML or efficient edge inference patterns
• Experience architecting B2B and Consumer facing applications

How You Embody Our Values:

At Linus, we live by Be Real, Be Wise, Be Noble, Be a Team, Be Masters of Our Craft, Think Big and Act Bold. In this role, you will:

• Be Real: communicate tradeoffs, risks, and results candidly—early and often
• Be Wise: select architectures and AI use cases with evidence, measurement, and clear mitigations
• Be Noble: prioritize privacy, safety, and clinical trust in ever