Senior Mobile Engineer

ROLE PURPOSE This role owns Lumen Dynamics ’s mobile engineering output end-to-end. You are responsible for designing, building, testing, and shipping high-performance mobile applications — primarily on iOS, with Android and cross-platform experience advantageous — that meet the exacting quality, security, and performance standards of a biometric identity platform used by tier-1 financial institutions. This is a hands-on engineering role operating at the intersection of product, design, and backend. You will work closely with product managers, backend developers, and QA teams across all stages of the development lifecycle — from requirements and architecture through to release and ongoing optimisation. You bring both technical depth and a high standard of craft: clean, maintainable code, user-driven ui, rigorous testing, and a genuine interest in getting the details right. Operating in a security-sensitive, compliance-heavy domain, you are expected to bring sound judgement to architecture decisions, stay current with the evolving mobile landscape, and contribute to a culture of technical excellence across the engineering team. ROLE TASKS & RESPONSIBILITIES Application Development & Architecture Design and build advanced applications for iOS (essential) and Android/Cross-Platform (advantageous), ensuring responsiveness, performance, and a seamless user experience across all supported devices Own mobile features from concept through to implementation: scoping, architecture, build, test, and release Collaborate with cross-functional teams to define, refine, and implement new mobile features that align with product strategy and client needs Identify and implement performance improvements that meaningfully enhance application responsiveness and reliability in production Stay current with mobile trends, emerging technologies, and best practices across iOS, Android, and cross-platform frameworks — and bring relevant opportunities to the team proactively Engineering Standards & Code Quality Write clean, maintainable, and efficient code in Swift and Objective-C (iOS — essential) and Java, Kotlin (Android — advantageous), and across cross-platform frameworks such as React Native or Flutter Apply SOLID principles and modern mobile architecture paradigms — including microservices and event-driven patterns — to produce code that scales and survives production Conduct thorough code reviews, providing constructive technical feedback and upholding engineering standards across the team Maintain clear and useful technical documentation covering architecture decisions, coding standards, and design rationale Optimise code for speed, scalability, and maintainability; identify and resolve technical debt proactively Testing, Debugging & Quality Assurance Conduct thorough testing of applications to identify and resolve bugs and performance issues before they reach production Apply TDD/BDD best practices and maintain well-tested, reliable code as a non-negotiable standard Work with QA teams to design and implement automated testing strategies that reduce manual effort and increase release confidence Debug and resolve production issues promptly, conducting root cause analysis and sharing learnings with the broader team UI/UX Implementation Use Claude Design to create attractive, intuitive, and consistent interfaces across all UI and UX flows Ensure mobile applications meet high-quality UI/UX standards and adhere to Apple and Android design principles throughout Translate design specifications into performant, pixel-accurate code that delivers a seamless end-user experience DevOps, CI/CD & Deployment Collaborate with DevOps teams to ensure smooth deployment processes, robust CI/CD pipelines, and clean code integration Use version control systems (Git) with discipline: clear branching strategies, meaningful commit messages, and clean pull request hygiene Contribute to improving deployment workflows, release automation, and build reliability across the mobile engineering function Collaboration & Communication Work effectively in an agile environment with cross-functional teams — product, design, QA, backend, and DevOps — to deliver high-quality mobile experiences on time Communicate technical concepts clearly and confidently to both technical and non-technical stakeholders Provide technical guidance and knowledge-sharing to team members; contribute to a culture of continuous learning and mutual accountability AI-Augmented Ways of Working Use AI tools as a standard, expected part of the role — a core professional competency, not optional Apply AI to accelerate code generation, debugging, documentation, test writing, and technical research Leverage AI to explore architectural options, evaluate trade-offs, and surface solutions faster than traditional approaches allow Model AI-augmented engineering practices for the broader team and contribute to embedding them into team norms Stay current with the evolving AI tooling landscape and proactivel