Principal Systems Reliability Engineer, Secure Federal Operations

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!

The Principal Systems Reliability Engineer is responsible for designing and implementing secure, scalable, and reliable technology solutions across cybersecurity, system architecture, networking, and platform operations. It combines expertise in security architecture, end‑to‑end solution design, and Dev Sec Ops /SRE practices to protect digital assets, enable cross‑domain integration, and optimize IT services. The position ensures the reliability and performance of software and systems supporting IT services by managing scalability, availability, latency, and security.

It involves designing and maintaining continuous integration and continuous delivery (CI/CD) pipelines, supporting cloud‑native application development, and driving operational excellence through automation and proactive monitoring. This role differentiates itself by combining strategic system design with hands‑on operational improvements and automation expertise. Success is measured by improved security posture, operational efficiency, faster software delivery, and enhanced customer experience—directly impacting organizational service quality and customer satisfaction.

This is a hybrid position required to be in‑office at least 2 days a week.

T-Mobile requires U.S. citizenship for certain roles within the organization. This role requires U.S. citizenship. Individuals hired into this role will be required to submit documentation proving U.S. citizenship within the first 7 days of hire - failure to do so will result in termination.

• Develop and implement system designs and architectures to improve software delivery speed and operational efficiency
• Lead architecture for cross‐domain programs, ensuring alignment with enterprise standards.
• Build and operate cloud‑native platforms (Kubernetes, service mesh, ingress, policy engines)
• Implement network segmentation, firewalls, VPNs, and Zero Trust principles.
• Contribute to advancing software delivery processes including cloud enablement and microservices containerization
• Deliver software solutions that enhance service availability, scalability, latency, and efficiency
• Manage environment provisioning and pipeline configurations to support automated server deployment
• Also responsible for other duties/projects as assigned by business management as needed

• 7+ years of progressive experience in systems architecture, platform engineering, or site reliability engineering, with a strong focus on security and operational excellence.
• Experience designing and implementing secure, scalable, and highly available systems across hybrid and cloud environments (Azure, AWS, or GCP).
• Experience in automation and scripting using Python, Go, Power Shell, or Bash.
• Knowledge of imaging processes and asset lifecycle management, including provisioning, patching, and compliance tracking preferred.
• Strong background in network architecture and security, including segmentation, VPNs, firewalls, and Zero Trust principles preferred.
• Experience with Dev Ops tools, such as, Ansible, Chef, Puppet, etc. Experience in Docker, Kubernetes, etc. is preferable.
• Experience with Application Performance Monitoring (APM) tools such as App Dynamics, and logging/observability tools like Splunk for troubleshooting and performance analysis.
• Experience working in a cloud environment (public/private).
• A ability to influence technology direction, lead architecture reviews, and collaborate across multiple teams preferred.
• Experience in incident and problem management, root cause analysis, and disaster recovery planning preferred.

• US citizenship (without dual citizenship).
• At least 18 years of age and legally authorized to work in the United States.
• Active security…