Senior React Native Engineer

LondonRemote

About the Role

Lumenpath Health is seeking a Senior React Native Engineer to join its four-person mobile team on a full-time, permanent basis. The company builds a mobile-first digital therapeutics app prescribed by UK NHS clinicians and private practices. The app is used by approximately 180,000 patients across chronic pain, sleep, and anxiety programs, and it is MHRA-registered as a Class IIa medical device.

This role is being hired as the company moves from clinical validation into scale, following its most recent clinical trial readout. With patient population growth expected to triple across 2026, the team is looking to add senior mobile engineering depth ahead of that growth. This is a product-critical role working on the core app experience rather than a lightweight wrapper around a web product.

The role can be based in London or remotely within the UK, with quarterly in-person weeks in London.

Key Responsibilities

Build and improve core program content delivery experiences, including CBT-I-style exercises, guided audio, and daily tracking features.
Develop mobile experiences that are reliable offline, performant on older devices, and accessible to users with significant cognitive or sensory limitations.
Contribute to clinical data collection workflows, including PROMs, ePRO, pain VAS sliders, and sleep diaries, with a strong focus on data integrity in a regulated environment.
Implement and maintain integrations with HealthKit on iOS, Health Connect on Android, NHS Login, and occasional Apple Watch or WearOS companion experiences.
Diagnose and resolve mobile performance issues, particularly for users running the app on older hardware.
Work across the React Native and native mobile layers, including debugging bridge issues and writing native modules when needed.
Contribute to a disciplined testing approach using Jest for the JavaScript layer, Detox for end-to-end testing, and manual QA on physical devices.
Collaborate within a regulated product environment where design history, audit trails, and careful change management are essential.

Required Qualifications

5+ years of experience building production mobile applications.
At least 3 years of experience working with React Native in production environments.
Demonstrated experience shipping a mobile application that supported a real business or production use case.
Strong React Native development experience with TypeScript.
Ability to work into native mobile code when needed, including Swift, Objective-C, Kotlin, or Java.
Strong testing discipline, including experience with Jest, Detox, and manual QA on physical devices.
Comfort working in a regulated environment with audit trails, controlled change processes, and documentation requirements.
Clearance to work in the UK at the time of application.
Ability to work UK hours.

Preferred Qualifications

Experience in healthcare, including NHS, MedTech, pharma, or digital health environments.
Experience with HealthKit or Health Connect.
Experience shipping an app through Apple App Store Review or Google Play review in a medical context.
Experience with accessibility standards and tools, including WCAG, VoiceOver, TalkBack, or Dynamic Type.
Experience with Fastlane or release automation.
Familiarity with mobile tooling and libraries such as Zustand, TanStack Query, React Navigation, Hermes, Reanimated, Sentry, App Store Connect, or Play Console.
Familiarity with Python, FastAPI, PostgreSQL, or AWS is helpful for context.

What We Offer

Base salary of £85,000 to £110,000, depending on seniority.
Meaningful equity through an EMI scheme.
Pension contribution of 7% employer and 3% employee.
Private health insurance through Bupa, including family coverage.
28 days of holiday, plus UK bank holidays and 3 wellness days.
A £2,000 learning budget for conferences, books, and courses.
A workstation or home-office budget.
Quarterly in-person weeks in London, including for remote UK team members.
The opportunity to work on a clinically validated, regulated digital therapeutics product used by patients across chronic pain, sleep, and anxiety programs.