Senior Mobile Developer (iOS / Android) - TS Cleared

We are seeking an experienced Senior Mobile Developer to design, build, and deploy secure, high-performance mobile applications supporting a mission-critical federal program in Washington, D.C. This is a hands-on engineering role for a developer who has personally owned the full mobile development lifecycle - from architecture and coding through testing, deployment, and sustainment. You will work alongside a collaborative team of engineers to deliver native and cross-platform applications that operate reliably in secure, high-stakes environments.

If you take pride in clean code, thoughtful architecture, and shipping products that make a real impact, this role offers the autonomy, technical challenge, and long-term stability of a direct-hire position.

What You'll Do

• Design, develop, and maintain native and/or cross-platform mobile applications for iOS and Android in a secure environment.
• Own features end to end - architecture, implementation, testing, deployment, and ongoing optimization.
• Collaborate with product owners, UX designers, and backend engineers to translate requirements into intuitive, performant mobile experiences.
• Write clean, well-documented, maintainable code and participate in peer code reviews.
• Integrate mobile applications with secure RESTful APIs, backend services, and authentication frameworks.
• Optimize application performance, security, and responsiveness across devices and OS versions.
• Apply secure coding practices and support accreditation, compliance, and DevSecOps requirements.

Active Top Secret clearance** (required to start).

• 7+ years of professional software development experience, with a strong concentration in mobile development.
• Demonstrated, hands-on expertise building native mobile applications using Swift / SwiftUI / Objective-C (iOS) and/or **Kotlin / Java (Android).
• Proficiency integrating mobile apps with RESTful APIs, microservices, and secure authentication (OAuth, SSO, PKI).
• Solid command of mobile architecture patterns (MVVM, MVC), version control (Git), and CI/CD pipelines.
• Experience with the full mobile development lifecycle, including testing frameworks, debugging, and App Store / enterprise deployment.
• Strong problem-solving skills and the ability to work independently in an onsite, collaborative team setting.
• Bachelor's degree in Computer Science, Software Engineering, or a related field (equivalent professional experience considered)., Experience with cross-platform frameworks (React Native, Flutter).
• Background developing for secure, federal, or DoD/IC environments.
• Familiarity with mobile device management (MDM), containerization, or secure mobile frameworks.
• Knowledge of cloud platforms (AWS, Azure) and DevSecOps practices., Keywords: Senior Mobile Developer, iOS Developer, Android Developer, Swift, SwiftUI, Kotlin, Java, mobile application development, cleared software engineer, Top Secret clearance, TS/SCI, secure mobile development, React Native, Flutter, DevSecOps, Washington DC, direct hire, federal software engineer*

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. Seneca Resources is proud to be an Equal Opportunity Employer, committed to fostering a diverse and inclusive workplace where all qualified individuals are encouraged to apply.