Senior Network Engineer- Core Network Fabric

Description
At Liberty, you'll thrive in a hybrid setting that fosters in-person collaboration, innovation and growth. This approach optimizes both remote and in-person interactions, enabling you to connect and ideate with your team and deepen valuable relationships across the company, while still enjoying the flexibility of remote work for focused tasks and projects. This position follows a hybrid work model (2 days onsite) and is open to candidates located in Portsmouth, NH; Boston, MA; Plano, TX; Indianapolis, IN; and Columbus, OH.
Role overview: We are seeking a Senior Network Engineer with deep, hands‑on experience across multiple modern networking platforms - including Cisco ACI, ONOS (or equivalent SDN controllers), and SONiC (Dell SONiC) - to design, deploy, automate, and operate resilient, secure, and scalable network fabrics across data center and cloud environments. The role blends architecture, implementation, automation, troubleshooting, and mentoring responsibilities.
Key responsibilities

• • Architect, deploy and operate core network fabrics that span controller‑based and disaggregated switching platforms (Cisco ACI, ONOS‑driven SDN, SONiC‑based switches).
  • Design and integrate underlay/overlay solutions (experienced with principles of EVPN‑VXLAN, BGP & OSPF) and multi‑tenant segmentation models.
  • Build and maintain automation and orchestration for provisioning, lifecycle management and configuration drift prevention using tools such as Python, Ansible, Terraform, CI/CD pipelines.
  • Lead complex troubleshooting across controller, switch ASIC/NOS, host, and overlay stacks; lead incident response and post‑mortems.
  • Implement telemetry and observability (gNMI/gRPC, NETCONF/RESTCONF, streaming telemetry, sFlow/NetFlow, Prometheus/Grafana) to drive monitoring and proactive operations.
  • Create, publish and monitor network performance trends and error rate dashboards from a variety of platform consoles and observability tools such as Splunk or DataDog.
  • Manage software/firmware lifecycle: upgrades, compatibility testing, rollback plans, and vendor coordination.
  • Enforce network security: ACLs, micro‑segmentation, QoS, and role‑based access for privileged systems.
  • Collaborate with cloud, platform, security and application teams to meet performance, reliability and compliance requirements.
  • Mentor junior engineers and maintain clear runbooks, playbooks, and architecture documentation.
  • Evaluate new technologies and run PoCs to inform roadmap and procurement decisions.

Qualifications

• 5+ years of professional network engineering experience, including production deployments and operations.
• Hands‑on experience with at least two of: VXLAN or OpenSource networking environments, Cisco ACI, ONOS (or comparable SDN controllers like OpenDaylight), and SONiC (Dell SONiC) on disaggregated hardware.
• Solid L2/L3 fundamentals and experience with EVPN‑VXLAN, BGP (including EVPN), OSPF, VLANs, multicast, and routing design.
• Proven automation and scripting skills (Python preferred) and experience with configuration tools (Ansible, Terraform, or comparable).
• Strong Linux skills (network namespaces, iproute2, systemd) and familiarity integrating networking with host/container platforms (Kubernetes).
• Experience with network telemetry/programmability and common observability stacks.
• Demonstrated ability to troubleshoot complex production incidents and to document resolution and mitigations.
• Bachelor's degree in Computer Science, Electrical Engineering or equivalent practical experience.

Preferred qualifications

• Advanced certifications such as CCNP/CCIE, or vendor certifications relevant to ACI or SONiC.
• Experience developing or customizing SDN controller applications, northbound/southbound APIs with ONOS.
• Familiarity with Dell SONiC specifics: image management, platform drivers, SONiC CLI/SDK, and ASIC behavior.
• Experience with privileged access management, secure network design, and compliance (SOC2, PCI, HIPAA).
• Exposure to P4/programmable data plane concepts and testing/CI for network code.

Skills & attributes

• Strong analytical and communication skills; able to present complex topics to cross‑functional audiences.
• Self‑starter who can lead projects end‑to‑end and influence technical decisions.
• Collaborative, mentoring mindset and commitment to documentation and operational excellence.

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.
At Liberty Mutual, our goal is to create a workplace where everyone feels valued, supported, and can thrive. We build an environment that welcomes a wide range of perspectives and experiences, with inclusion embedded in every aspect of our culture and reflected in everyday interactions. This comes to life through comprehensive benefits, workplace flexibility, professional development opportunities, and a host of opportunities provided through our Employee Resource Groups. Each employee plays a role in creating our inclusive culture, which supports every individual to do their best work. Together, we cultivate a community where everyone can make a meaningful impact for our business, our customers, and the communities we serve.
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

USD $104000.00 - $197000.00