Senior Network Engineer- Core Network Fabric

Liberty Mutual•Boston, MA

32d•Hybrid

About The Position

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, handsâon 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.

Requirements

5+ years of professional network engineering experience, including production deployments and operations.
Handsâon 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 EVPNâVXLAN, 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.

Nice To Haves

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.

Responsibilities

Architect, deploy and operate core network fabrics that span controllerâbased and disaggregated switching platforms (Cisco ACI, ONOSâdriven SDN, SONiCâbased switches).
Design and integrate underlay/overlay solutions (experienced with principles of EVPNâVXLAN, BGP & OSPF) and multiâtenant 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 postâmortems.
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, microâsegmentation, QoS, and roleâbased 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.