Principal Engineer, Platform

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

At T Mobile, we don't just build technology - we empower people. We believe in investing in YOU - your growth, your leadership, and your impact. We're unstoppable when individuals like you come together to solve bold challenges, inspire innovation, and create systems that power the future.

As a Principal Platform Engineer, you'll be a key technical leader shaping the platform foundations that power T Mobile's Device Finance system. You will define the strategic platform architecture, lead modernization of legacy and cloud workloads, and deliver high resiliency, high security, high performance capabilities that are data driven and AI empowered. Your vision and hands on leadership will accelerate time to market, elevate developer productivity, and optimize cost and reliability at scale.

Job Responsibilities:

• Set platform strategy & reference architecture for computing, data, integration, observability, AIOps, and security across multiple clouds and on‑prem environments.
• Define and architect scalable, high‑performance solutions and shared platform services; set technical direction across development teams.
• Lead platform modernization (legacy refactoring, re‑platforming to Kubernetes/containers, enterprise‑wide architecture optimization).
• Establish coding and system design standards for microservices (Spring Boot), APIs (REST/gRPC), event‑driven patterns, idempotency, and zero‑downtime releases.
• Own DevOps enablement: GitLab/GitHub CI/CD, artifact strategy, blue/green & canary deployments, rollout/rollback guardrails.
• Drive platform performance and reliability: SLOs/error budgets, capacity planning, auto‑scaling, disaster recovery, and cost‑efficient infrastructure scaling.
• Implement end‑to‑end observability and AIOps:
  • Build data pipelines for metrics, logs, traces, events, and business KPIs (Open Telemetry‑first).
  • Deploy anomaly detection, dynamic thresholds, noise reduction, and event correlation to cut alert fatigue and reduce MTTD/MTTR.
  • Create automated triage and remediation runbooks; integrate with incident and ChatOps workflows for rapid resolution.
  • Generate AI/LLM‑assisted incident summaries, RCA drafts, and runbook suggestions to speed learning and response.
• Champion security & compliance: threat modeling, secrets & identity, RBAC/ABAC, auditability (e.g., SOX/PCI), secure SDLC controls and policy guardrails for AI/AIOps use.
• Lead integrations with third‑party platforms and internal systems (e.g., OFSLL and adjacent financial services), API gateways, and shared services.
• Steward data platforms: performance and resiliency for Oracle DB and MongoDB, caching strategies, schema/versioning governance.
• Enable AI/ML and developer tooling: platform capabilities for model serving/AI agents, golden paths, templates, and inner‑source components that boost dev velocity.
• Advance the technology roadmap: evaluate, pilot, and adopt new platform capabilities across AWS/Azure/GCP/OCI, optimizing for reliability and cost.
• Run technical governance: design reviews, security/ops standards, architectural decision records; mentor and coach engineers across teams.

Education & Work Experience (Required/Preferred)

• Bachelor's degree in computer science, Software/Computer Engineering, or related field (required); Master's in CS/Data/Systems (preferred).
• 10+ years building and operating platform‑scale, cloud‑native systems; 5+ years leading architecture/technical strategy across multiple teams.
• Hands‑on expertise in Java/Spring Boot microservices, distributed systems, and API design (REST/gRPC).
• 3+ years implementing CI/CD with GitLab/GitHub and IaC; strong experience with Kubernetes/containers and at least one major cloud (AWS, Azure, GCP, or OCI).
• Demonstrated experience with Oracle (SQL) and MongoDB (NoSQL) performance and resiliency.
• Experience enabling AI/ML workloads or platform features (model serving, AI agents, feature stores) is preferred.
• AIOps exposure preferred: deploying anomaly detection, correlation, automated remediation, LLM/agent‑assisted ops, and SLO‑driven alerting
• 1+ year mentoring/coaching engineers; proven cross‑functional leadership with Product/TPM/Architecture/SRE/SecOps.

• Knowledge, Skills and Abilities:
• Strategic platform thinking: align platform capabilities with business outcomes; create pragmatic roadmaps.
• Technical leadership: lead cross‑functional engineering initiatives; influence without authority; scale best practices.
• Platform engineering depth: Spring Boot, Kubernetes, Kafka, RabbitMQ, Oracle DB, MongoDB; network fundamentals and performance tuning.
• Observability & operations excellence: design for reliability; instrument services; optimize SLOs; drive MTTD/MTTR down.
• Security by design: deep understanding of platform security, secrets, identity, data protection, and compliance in regulated finance. AI/AIOps guardrails and auditability.
• Cost & performance optimization: measure and tune infra parameters, right‑size capacity, and drive efficiency at scale.
• Collaboration & communication: clear written/spoken communication; stakeholder management across products, finance, and technology.
• Innovation mindset: evaluate and integrate new cloud/platform services and AIOps services; enable AI/ML and modern developer experience.

Licenses and Certifications:

• Certified Information Systems Security Professional (CISSP) An advanced-level certification for IT pros serious about careers in information security. It covers critical topics in security today, including cloud computing, mobile security, and application development security. (Preferred)
• AWS Certified Solutions Architect: Certification that validates the ability to design and deploy scalable, highly available, and fault-tolerant systems on AWS. It is crucial for roles requiring expertise in AWS platform management and architectural design. (Preferred)
• Certified Kubernetes Administrator (CKA): A certification that demonstrates the ability to design, build, configure, and expose cloud-native applications for Kubernetes, an essential skill for roles involving containerized applications and microservices architectures. (Preferred)

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

Travel:
Travel Required (Yes/No): No

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

Base Pay Range: $120,500 - $217,500

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 positions in Customer Care are eligible for monthly bonuses based on individual and/or team performance. To find the pay range for this role based on hiring location, click here.

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 www.t-mobilebenefits.com.

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, 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 ApplicantAccommodation@t-mobile.com or calling 1-844-873-9500. 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.