What are the responsibilities and job description for the Principal Network Engineer position at Liberty Mutual Insurance Group?
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. 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. 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. 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. 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.