Principal Network Engineer

Description

Job title: Principal Network Engineer - Cloud-Native Voice / Ribbon SIP

Role summary

We are seeking a Principal Network Engineer to own the design, deployment and lifecycle of our Ribbon-based SIP telephony infrastructure and contribute to the definition of the architecture and build-out of a cloud native platform for carrier-grade voice traffic. This is a hands-on role combining deep SIP/VoIP networking knowledge with Kubernetes, automation, CI/CD and DevOps software engineering skills. You will set technical direction, build production-ready systems, and partner with software, SRE and product teams to deliver a scalable, observable and secure voice platform.

What you'll do

• Contribute to architectural patterns and implementation of SIP signaling and media infrastructure based on Ribbon SIP solutions (SBCs, proxies, session management).
• Design and build a cloud-native voice platform to run SIP control-plane and media-plane components on Kubernetes (EKS/GKE/AKS), focusing on scale, low latency and resiliency.
• DevOps implementation via CI/CD and deployment pipelines for containerized voice services (Git-based workflows, automated builds, testing, and progressive deployments).
• Automate infrastructure and operational processes using IaC and configuration management (Terraform/CloudFormation, Ansible, Helm).
• Design and implement containerization, service discovery, networking, and traffic routing for real-time voice (Multus/CNI, SR-IOV, QoS, service mesh as appropriate).
• Build and maintain robust monitoring, alerting and observability for SIP and media metrics (Prometheus/Grafana, ELK, RTCP, SIP traces, distributed tracing).
• Ensure security and compliance for voice traffic (TLS/SRTP, SBC security policies, firewalling, encryption, role-based access) to meet/exceed established industry standards such as PCI, NYDFS, and other similar evolving practices.
• Define and drive SLOs/SLAs, capacity planning, performance testing and call-quality monitoring.
• Create and maintain runbooks, playbooks and support automation for incident response and DR scenarios; participate in on-call rotations as needed.
• Mentor engineers, establish best practices and standards, conduct peer reviews with architecture and collaborate with product, SRE and software teams.

Required qualifications

• 8+ years designing, implementing and operating SIP/VoIP networks and systems, with demonstrable experience working with Ribbon SIP telephony products.
• Strong hands-on experience with Kubernetes (production clusters, operators/CRDs, networking, security and scaling).
• Practical experience with CI/CD pipelines and deployment automation (Jenkins, GitLab CI, ArgoCD, Tekton or equivalent).
• Proficient software engineering skills - experience coding and scripting (Python, Go, or similar), writing automated tests and production-quality automation.
• Proven experience with infrastructure-as-code tooling (Terraform, CloudFormation) and container packaging (Docker, Helm).
• Deep understanding of RTP/SRTP, SIP signaling (REGISTER/INVITE/PRACK/etc.), media handling, NAT traversal, and SBC behavior.
• Experience with cloud providers and managed Kubernetes (AWS/GCP/Azure) and cloud-native managed services.
• Strong knowledge of networking (TCP/UDP, QoS, UDP load balancing, BGP, routing) and security best practices for real-time communications.
• Excellent troubleshooting skills for high-volume, low-latency systems and experience operating in a 24x7 production environment.

Preferred qualifications

• Prior experience building high-scale cloud-native voice platforms (SaaS voice, CPaaS or telco-grade platforms).
• Significant experience with Ribbon product line (SBC/PSX/RAMP/Analytics) and associated management/orchestration APIs.
• Experience with voice testing and load tools (SIPp, Hammer, PJSIP) and call-quality measurement tools (MOS, R-factor).
• Knowledge of observability tools (Prometheus, Grafana, Jaeger, ELK) and call trace analysis.
• Cloud and networking certifications (CCNP/CCIE, AWS/GCP/Azure certified) or Ribbon vendor certification.
• Experience with service mesh, eBPF or advanced Kubernetes network plugins for media acceleration.

Key competencies

• Strong system-design abilities with a bias for automation and repeatability.
• Clear communicator capable of translating technical trade-offs to stakeholders and mentoring teams.
• Proven track record delivering production systems end-to-end: design, build, deploy, operate and improve.
• Comfortable working in cross-functional Agile teams and driving engineering excellence.

Qualifications

• Bachelor`s degree in Computer Science or a related discipline and at least eight years of solid work experience in network management or an equivalent combination of education and work experience.
• Requires analytical ability, strong judgement and problem analysis as well as a broad knowledge of business function(s) and Network and IT industry business issues.
• Highly developed communication, negotiation, presentation and consensus building skill required.
• Thorough knowledge of business objectives, strategies and operations required.
• Thorough knowledge of IT concepts, strategies, and methodologies as well as practices and procedures.

You will shape how voice services are delivered across our platform, enabling secure, reliable and scalable real-time communications for customers. This role combines deep telecom expertise with modern cloud-native engineering - a great opportunity to lead the next generation of voice infrastructure.

About Us
Pay Philosophy: The typical starting salary range for this role is determined by a number of factors including skills, experience, education, certifications and location. The full salary range for this role reflects the competitive labor market value for all employees in these positions across the national market and provides an opportunity to progress as employees grow and develop within the role. Some roles at Liberty Mutual have a corresponding compensation plan which may include commission and/or bonus earnings at rates that vary based on multiple factors set forth in the compensation plan for the role.

As a purpose-driven organization, Liberty Mutual is committed to fostering an environment where employees from all backgrounds can build long and meaningful careers. Through strong relationships, comprehensive benefits and continuous learning opportunities, we seek to create an environment where employees can succeed, both professionally and personally.

At Liberty Mutual, we believe progress happens when people feel secure. By providing protection for the unexpected and delivering it with care, we help people embrace today and confidently pursue tomorrow.

We are dedicated to fostering an inclusive environment where employees from all backgrounds can build long and meaningful careers. By actively seeking employee feedback and amplifying the voices of our seven Employee Resource Groups (ERGs), which are open to all, we create an environment where every individual can make a meaningful impact so we continue to meet the evolving needs of our customers.

We value your hard work, integrity and commitment to make things better, and we put people first by offering you benefits that support your life and well-being. To learn more about our benefit offerings please visit: https://LMI.co/Benefits

Liberty Mutual is an equal opportunity employer. We will not tolerate discrimination on the basis of race, color, national origin, sex, sexual orientation, gender identity, religion, age, disability, veteran's status, pregnancy, genetic information or on any basis prohibited by federal, state or local law.

Fair Chance Notices

• California
• Los Angeles Incorporated
• Los Angeles Unincorporated
• Philadelphia
• San Francisco

Client-provided location(s): Columbus, OH, Boston, MA, Indianapolis, IN, Flexible / Remote, Plano, TX, Portsmouth, NH

Job ID: liberty_mutual-2025-72375-en_4

Employment Type: OTHER

Posted: 2025-09-27T20:09:15