Principal Software Engineer

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 OverviewThis role sets technical direction for the systems that make T-Mobile's data usable across customer-facing applications, analytics, and AI-driven products. It involves designing and building high-performance services and APIs: the distributed data stores, low-latency access layers, and real-time sync mechanisms that deliver the right data to each consumer within strict latency and reliability targets. The role requires applying seasoned engineering judgment to solve complex systems challenges and to make recommendations on architecture, technology selection, and API and service design. Success is measured by the scalability and reliability of these systems, the strength of technical leadership provided to engineers, and the ability to influence engineering decisions across the organization. The work impacts the organization by enabling the real-time, AI-ready capabilities that power better products and customer experiences.Job Responsibilities:Design and build serving infrastructure for AI use cases including vector databases, graph databases, and agent-facing data patternsDesign Infrastructure-as-Code blueprints for provisioning serving stores, sync pipelines, and APIs in a repeatable, governed wayPartner with business teams and other technical teams to drive technical decision making, mentor engineers, and contribute to reusable blueprints and reference implementations.Design and develop high-performance data stores, real-time sync pipelines, and governed APIs that deliver data at the latency and scale each use case requiresDrive engineering projects to deliver software solutions that meet technical requirements and quality standardsProvide technical leadership by mentoring engineers and influencing technology and policy decisions across the organizationEvaluate and apply technology strategies that align with business goals and system requirementsDevelop innovative software designs and improvements that enhance existing systems and processesProduce clear technical documentation and architecture descriptions for internal and external stakeholdersAlso responsible for other duties/projects as assigned by business management as neededRequired 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)Required Knowledge, Skills and Abilities:AI/ML InfrastructureKnowledge GraphsVector DatabasesStreaming and caching architectureAPI Design and GovernanceMCP-Style tooling or agent facing data access patternsData sync pipelinesAnalytics, Collaboration and Communication skillsAnalytical Thinking, Cloud computing, Customer Service and Leadership skillsSoftware Development and Technical Writing skillsAt least 18 years of ageLegally authorized to work in the United StatesTravel:Travel Required (Yes/No): YesDOT Regulated:DOT Regulated Position (Yes/No): NoSafety Sensitive Position (Yes/No): NoCompensation Range:Bellevue, WA: $173,500 to $234,700Atlanta, GA: $151,200 to $204,600Total Target Cash Earnings Opportunity: $160,200 - $288,840National Base Pay Range: $133,500 - $240,700The Total Target Cash Earnings Opportunity represents the expected total cash compensation for this role at target performance, combining base salary and annual incentive opportunity. Actual earnings may be higher or lower depending on individual performance and overall company results. The base pay range reflects the compensation component of this opportunity. The 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. To find the pay range for this role based on hiring location, T-Mobile, employees in regular, non-temporary roles are eligible for an annual bonus or periodic sales incentive or bonus, based on their role. Corporate employees are eligible for a year-end bonus based on individual and/or company performance and which is set at a percentage of the employee’s eligible earnings in the prior year. Certain positions in Customer Care are eligible for monthly bonuses based on individual and/or team performance. The incentive component included in the Total Target Cash Earnings Opportunity reflects target performance. Actual earnings included in the Total Target Cash Earnings Opportunity reflect target performance; actual payouts may vary. At T-Mobile, our benefits exemplify the spirit of One Team, Together! A big part of how we care for one another is working to ensure our benefits evolve to meet the needs of our team members. Full and part-time employees have access to the same benefits when eligible. We cover all of the bases, offering medical, dental and vision insurance, a flexible spending account, 401(k), employee stock grants, employee stock purchase plan, paid time off and up to 12 paid holidays - which total about 4 weeks for new full-time employees and about 2.5 weeks for new part-time employees annually - 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, and voluntary long-term care insurance. We don't stop there - eligible employees can also receive mobile service & home internet discounts, pet insurance, and access to commuter and transit programs! To learn about T-Mobile’s amazing benefits, check out .Never stop growing!As part of the T-Mobile team, you know the Un-carrier doesn’t have a corporate ladder–it’s more like a jungle gym of possibilities! We love helping our employees grow in their careers, because it’s that shared drive to aim high that drives our business and our culture forward. By applying for this career opportunity, you’re living our values while investing in your career growth–and we applaud it. You’re unstoppable!T-Mobile USA, Inc. is an Equal Opportunity Employer. All decisions concerning the employment relationship will be made without regard to age, race, ethnicity, color, religion, creed, sex, sexual orientation, gender identity or expression, genetic information, national origin, religious affiliation, marital status, citizenship status, veteran status, the presence of any physical or mental disability, or any other status or characteristic protected by federal, state, or local law. Discrimination, retaliation or harassment based upon any of these factors is wholly inconsistent with how we do business and will not be tolerated.Talent comes in all forms at the Un-carrier. If you are an individual with a disability and need reasonable accommodation at any point in the application or interview process, please let us know by emailing View email address on click.appcast.io or calling View phone number on click.appcast.io. Please note, this contact channel is not a means to apply for or inquire about a position and we are unable to respond to non-accommodation related requests.SummaryLocation: Bellevue, Washington; Atlanta, GeorgiaType: Full timePosted: 2026-10-12Country: United States of AmericaRequisition: REQ361620Posting ID: c47299772e4e102eed1092bb43370000