React Native Engineer

We are excited to be working with a Series B HealthTech scale-up looking to hire a high-calibre contract Senior React Native Engineer into their UK business.

Having already achieved profitability and with hundreds of household-name enterprise clients, they're looking to add fuel to their mobile engineering team fire in the shape of an experienced contract engineer.

This contractor could be based fully-remote anywhere in the UK or hybrid out of their London HQ - the choice is entirely yours.

As Senior React Native Engineer you will work on :

• Bridging the Native Gap : You will manage the complex intersection of React Native and native mobile code. This includes debugging mixed builds, writing or maintaining Native Modules, and ensuring seamless interoperability between JS, Swift / Obj-C, and Java / Kotlin / C++.
• Architecture & Modernization : You will tackle high-level architectural updates, such as ensuring our Android builds align with modern memory page size requirements (NDK alignment) and managing complex library upgrades against dependency conflicts.
• Security & Hardening : As a HealthTech company, trust is everything. You will implement and maintain advanced security features, such as certificate pinning, build protection, and environment integrity checks (e.g. jailbreak / root detection).
• Complex Feature Implementation : You will lead the integration of third-party SDKs (such as video conferencing tools) and critical user flows like Multi-Factor Authentication (MFA).
• Embedded Collaboration : You will operate as a core member of the team-participating in sprint planning, stand-ups, and demos. You will contribute to code reviews, help unblock peers, and engage in technical discussions in Slack to drive the product forward.

• Deep React Native Expertise : You have years of experience not just building screens, but managing the "guts" of the framework. You understand the bridge, the build systems (Gradle / Cocoapods / SPM), and the release pipeline.
• Native Fluency : You aren't afraid to open Xcode or Android Studio. You have experience with native code (Java / Kotlin or Obj-C / Swift) and understand how to troubleshoot issues that originate in the native layer or NDK.
• Security Mindset : You understand mobile security best practices and have experience implementing protection layers in a commercial application.
• Staff-Augmentation Mindset : You view yourself as part of the team. You are communicative, present, and invested in the quality of the codebase, not just the completion of a contract. If and as opportunities to work on the node.js backend present themselves, you're ready to jump in.
• Resilience & Problem Solving : You are unfazed by "red builds." You know how to hunt down obscure build errors, untangle dependency hell, and get the app running smoothly on the latest OS versions.