Principal Software Engineer iOS - National Retail

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!

Job Overview
This Principal Engineer, Software role is essential for designing, implementing, and deploying scalable software solutions that meet customer requirements and support high availability environments. It involves collaborating with engineers to develop software components using technologies such as virtualization, microservices, software-defined networking, network functions virtualization, and big data platforms. The role requires applying judgment to resolve complex technical issues and making recommendations for software architecture and design. Success is measured by the effectiveness of software solutions, technical leadership contributions, and the ability to influence technology decisions. The work impacts the organization by enabling advanced software capabilities that improve operational efficiency and customer experience.

Job Responsibilities:

• Define and evolve the iOS engineering vision, setting architectural standards and long-term direction; lead high-complexity design to raise the bar for quality and scalability.

• Serve as a cross-functional leader across product, design, backend, QA, AI, and executives; align priorities, resolve dependencies, and mentor engineers to elevate technical capability.

• Drive mobile technology strategy by identifying platform and industry inflection points; translate into roadmap investments and lead adoption of AI-powered capabilities (on-device ML, personalization, conversational UX).

• Evaluate and apply technology strategies that align with business goals, driving scalable, high-impact system design improvements.

• Champion technical clarity through org-wide documentation standards (ADRs, runbooks, API governance, design templates) to scale knowledge and accelerate onboarding.

• Also responsible for other duties/projects as assigned by business management as needed.

Education and Work Experience:

• Bachelor's Degree plus 7 years of related work experience OR Advanced degree with 5 years of related experience (Required)

• Acceptable areas of study include Computer Science or Engineering (Required)

• 7-10 years Technical engineering experience (Required)

• Experience developing iOS applications using Swift, Objective-C, SwiftUI, and the iOS SDK 

Knowledge, Skills and Abilities:

• Communication (Required)

• Customer Service (Required)

• Analytics (Required)

• Technical Writing (Required)

Preferred Skills:

• Experience leading and scaling mobile retail apps in production, with a focus on reliability and performance.

• Deep knowledge of iOS architecture (MVC, MVVM, Coordinator, VIPER) and ability to influence standards across teams.

• Experience designing integrations (APIs, Core Data, SDKs) and contributing to CI/CD practices (GitLab or similar).

• Familiarity with observability tools (Firebase or similar) to support performance and system health.

• Exposure to AI-powered solutions (LLMs, personalization) and mobile security best practices (OAuth, encryption).

Licenses and Certifications:

• At least 18 years of age
• Legally authorized to work in the United States

Travel:
Travel Required (Yes/No): Yes, may require up to 10% travel based on business needs.

DOT Regulated:
DOT Regulated Position (Yes/No): No
Safety Sensitive Position (Yes/No): No
 

Base Pay Range: $133,500 - $240,700

Corporate Bonus Target: 20%

The pay range above is the general base pay range for a successful candidate in the role. The successful candidate’s actual pay will be based on various factors, such as work location, qualifications, and experience, so the actual starting pay will vary within this range.

At T-Mobile, employees in regular, non-temporary roles are eligible for an annual bonus or periodic sales incentive or bonus, based on their role. Most Corporate employees are eligible for a year-end bonus based on company and/or individual performance and which is set at a percentage of the employee’s eligible earnings in the prior year. Certain po