About the position
At T-Mobile, we invest in YOU! Our Total Rewards Package ensures that employees get the same big love we give our customers. All team members receive a competitive base salary and compensation package - this is Total Rewards. Employees enjoy multiple wealth-building opportunities through our annual stock grant, employee stock purchase plan, 401(k), and access to free, year-round money coaches. That's how we're UNSTOPPABLE for our employees! We are seeking a highly skilled and experienced Sr. iOS Engineer to help shape the future of the T-Mobile T-Life App. In this role, you'll collaborate with a talented team of mobile engineers to design, implement, and maintain high-quality iOS features that meet both business goals and user needs. You'll be responsible for delivering scalable, performant, and secure mobile solutions that drive an exceptional customer experience across T-Mobile's mobile ecosystem. The ideal candidate brings deep expertise in modern iOS development practices-including architecture design, testing strategies, and performance optimization-along with strong collaboration and mentorship skills. You'll contribute to technical direction, ship features to production, guide best practices, and grow within a culture that values innovation, ownership, and continuous learning.
Responsibilities
- Design, build, and maintain iOS features using Swift and the latest frameworks and tools.
- Deliver high-performance, secure, and user-friendly features that meet platform and business requirements.
- Write unit and integration tests to ensure quality and reliability across the app.
- Debug and profile performance bottlenecks across devices and OS versions.
- Collaborate with Product and Design teams to explore innovative features and user flows.
- Prototype and implement solutions that solve complex problems or introduce new capabilities.
- Contribute to feature planning and development cycles that align with strategic product objectives.
- Help define and enforce architectural patterns (MVVM, Coordinator, etc.) for codebase scalability.
- Guide junior developers through code reviews, pair programming, and design discussions.
- Promote clean code, modular design, and reusable components across the platform.
- Lead or participate in engineering workshops, tech talks, and continuous improvement initiatives.
- Work within an Agile environment using GitLab for CI/CD, source control, and merge request workflows.
- Collaborate cross-functionally with QA, backend teams, and platform engineers.
- Identify and address system-level risks or architectural gaps early in the dev lifecycle.
- Create and maintain clear technical documentation for features, APIs, and workflows.
- Communicate engineering decisions and trade-offs with stakeholders and team leads.
Requirements
- Bachelor's Degree in Computer Science, Engineering, or related field (required).
- 4-7 years' experience developing iOS apps using Swift (Objective-C and C++ a plus).
- Expertise with Xcode, SwiftUI, UIKit, Interface Builder, and Apple SDKs.
- Experience with Core Data, RESTful APIs, and networking frameworks.
- Strong grasp of iOS memory management, concurrency (GCD), and threading.
- Working knowledge of architectural patterns like MVVM, MVC, and Coordinator.
- Solid understanding of common iOS design patterns: Singleton, Delegate, Observer.
- Proficient with GitLab, Git workflows, and continuous integration practices.
- Experience building maintainable, testable codebases.
- Skilled in writing unit tests and performing integration testing.
- Familiarity with Apple Human Interface Guidelines.
- Understanding of iOS security best practices, including secure storage, communication (HTTPS), and OAuth.
- Strong problem-solving and debugging skills.
- Clear communication and ability to work collaboratively across teams.
- A commitment to continuous learning and growth in mobile development.
Nice-to-haves
- Familiarity with accessibility best practices (WCAG, VoiceOver testing).
- Experience integrating with backend services, feature flag systems, or A/B testing platforms.
- Contributions to internal tooling, SDKs, or design systems.
Benefits
- Medical, dental and vision insurance.
- Flexible spending account.
- 401(k).
- Employee stock grants.
- Employee stock purchase plan.
- Paid time off and up to 12 paid holidays.
- Paid parental and family leave.
- Family building benefits.
- Back-up care.
- Enhanced family support.
- Childcare subsidy.
- Tuition assistance.
- College coaching.
- Short- and long-term disability.
- Voluntary AD&D coverage.
- Voluntary accident coverage.
- Voluntary life insurance.
- Voluntary disability insurance.
- Voluntary long-term care insurance.
- Mobile service & home internet discounts.
- Pet insurance.
- Access to commuter and transit programs.
