Senior Mobile UI Developer

Position Title: Senior Mobile UI Developer (React Native)

Location: Hybrid in Birmingham, AL

Position Status: Contract to Hire

About the Role

We are seeking a Senior Mobile UI Engineer to play a key role in modernizing a large-scale, internal mobile application used daily by approximately 5,000 employees. This is a hands-on, senior-level role focused on building secure, high-performance mobile applications (iOS/Android)-not web sites or responsive web pages.

You will work on a mobile application with third-party system integrations, including Microsoft Dynamics 365, Power BI, and other enterprise platforms, while helping evolve the app's architecture, UI patterns, and security model.

What You'll Do

• Design, develop, and maintain production-grade mobile application features using React Native and TypeScript
• Contribute to the modernization of an existing enterprise mobile app, improving performance, usability, and scalability
• Build robust, reusable UI components and help shape long-term mobile architecture and design patterns
• Integrate mobile UI with complex backend systems and third-party APIs, including Microsoft platforms (Dynamics 365, Power BI)
• Implement and maintain secure authentication flows, including multi-factor and two-factor authentication
• Optimize mobile app performance across devices, OS versions, and network conditions
• Write clean, testable, well-documented code with strong test coverage (unit and integration testing)
• Collaborate closely with UX/UI designers, backend engineers, product owners, and platform teams
• Participate in code reviews, architectural discussions, and Agile ceremonies
• Mentor and support other developers, promoting best practices and high engineering standards
• Stay current with mobile development trends, tools, and frameworks to continuously improve the app and team

Required Qualifications

• 10+ years of professional software development experience, with significant hands-on mobile application experience
• Strong React Native experience building real-world mobile apps (iOS and Android)
• Excellent TypeScript and modern JavaScript (ES6+) skills
• Experience building and maintaining mobile apps used at scale (internal or external)
• Deep understanding of mobile UI/UX principles, performance optimization, and device constraints
• Hands-on experience with unit and integration testing (Jest, React Testing Library or similar)
• Solid knowledge of mobile application state management (Redux, Zustand, Recoil, etc.)
• Experience integrating with RESTful APIs and/or GraphQL
• Familiarity with CI/CD pipelines, Git-based version control, and automated testing
• Strong problem-solving skills, attention to detail, and the ability to work effectively in a collaborative team

Nice to Have

• Experience with Ionic / Capacitor or hybrid mobile platforms
• Exposure to Java-based backends and enterprise APIs
• Experience integrating with Microsoft enterprise tools (Dynamics 365, Power BI, Azure services)
• Knowledge of mobile security best practices, authentication, and authorization
• Previous experience modernizing or refactoring legacy mobile applications

About Seneca Resources:

At Seneca Resources, we are more than just a staffing and consulting firm, we are a trusted career partner. With offices across the U.S. and clients ranging from Fortune 500 companies to government organizations, we provide opportunities that help professionals grow their careers while making an impact.

When you work with Seneca, you're choosing a company that invests in your success, celebrates your achievements, and connects you to meaningful work with leading organizations nationwide. We take the time to understand your goals and match you with roles that align with your skills and career path. Our consultants and contractors enjoy competitive pay, comprehensive health, dental, and vision coverage, 401(k) retirement plans, and the support of a dedicated team who will advocate for you every step of the way.