Network Engineer II

Five9 is a leading provider of cloud contact center software, bringing the power of cloud innovation to customers worldwide. They are seeking a Network Engineer II to operate in a 24/7 SaaS environment, focusing on complex LAN infrastructure initiatives and driving operational excellence across various platforms while mentoring junior engineers.

Responsibilities:

• Own end-to-end troubleshooting of complex LAN connectivity, firewall policy, and load balancer issues, and drive resolution with customers and internal teams
• Conduct in-depth analysis of network incidents, identify root causes, and implement preventive measures to reduce repeat occurrences
• Lead and coordinate responses to network and security incidents, ensuring timely resolution and minimizing potential impacts
• Participate in on-call rotation following the Sun Model schedule; provide technical leadership during outages and lead post-incident root cause analysis and corrective action planning
• Lead the review, analysis, and execution of network change requests within the data-center fabric domain, ensuring adherence to change management and risk-mitigation standards
• Lead and drive LAN infrastructure projects involving Cisco Nexus switching, Palo Alto firewalls, F5 load balancers, and NDFC fabric management
• Partner with cross-functional stakeholders to design and deliver next-generation data-center fabric architectures, leveraging VXLAN, Cisco Nexus Dashboard, Kubernetes networking (Calico), and AI/ML-enabled networking
• Manage and operate data-center fabric services across hybrid and multi-cloud environments — on-premises Cisco Nexus infrastructure, GCP, and AWS
• Perform traffic engineering and capacity planning to guide long-term infrastructure investments
• Develop and maintain technical roadmaps, architecture standards, and configuration policies for LAN, firewall, and load balancer environments
• Manage and maintain existing network infrastructure (Nexus, Palo Alto, F5), ensuring reliability, performance, and equipment lifecycle planning
• Develop and report operational and performance metrics using observability platforms including Prometheus, Grafana, and SolarWinds
• Define, measure, and report site reliability using SLI/SLO
• Maintain operational focus on the data-center fabric while coordinating cross-team efforts with network security and load balancing functions to ensure end-to-end service reliability
• Analyze historical network incidents to identify systemic issues and inform preventive engineering
• Drive automation strategy and execution using Ansible, Terraform, Python, and CI/CD pipelines for provisioning, configuration, and monitoring
• Implement automated remediation to prevent recurrence of known issues
• Demonstrate and scale a culture of automation across engineering and operations teams
• Track and manage projects, processes, and technology initiatives across the team, ensuring alignment, visibility, and timely execution
• Maintain runbooks, topology diagrams, and SOPs
• Manage overall network security including routing policies, Palo Alto firewall rules, and access controls to protect infrastructure
• Own all operational aspects of network security infrastructure — OS maintenance, vulnerability management, capacity planning, lifecycle management, and certificate administration

Requirements:

• Bachelor's degree in computer science or a related technical field preferred, or equivalent practical experience
• Minimum 5–10 years of experience in medium-to-large networks, IP routing, switching, and security principles in a production SaaS or enterprise environment, including experience as a technical subject matter expert
• Deep hands-on expertise with Palo Alto firewalls — security policy design, Panorama management, Global Protect VPN, and threat prevention
• Advanced experience with F5 BIG-IP — LTM, GTM, iRules, SSL offloading, and application delivery configurations
• Expert-level knowledge of Cisco Nexus 9k/7k/5k/2k, NX-OS, and NDFC, including VXLAN/EVPN fabric deployments
• Extensive hands-on experience with software-defined networking (SDN) — OpenStack Neutron and Calico (Kubernetes)
• Hands-on skills with Cisco IOS required; Nexus OS and NDFC expertise required
• Proven experience automating infrastructure processes and deployments using Ansible, Terraform, Python, and CI/CD pipelines, with demonstrated ability to drive and scale a culture of automation
• Demonstrated expertise in LAN protocols and technologies — VXLAN, EVPN, OSPF, BGP, MPLS, and STP/RSTP — with strong hands-on experience with dynamic routing protocols, particularly BGP in data-center fabric environments
• Experience implementing solutions involving large data centers, inter-business routing plans, site-to-site IPSec VPNs, firewalls, and MPLS VPNs
• Strong experience with network monitoring and observability tools — SolarWinds, Prometheus, Grafana, NetFlow, SNMP, and packet brokers
• Demonstrated experience with incident response, root cause analysis, change management, and operational governance; experience defining, measuring, and reporting reliability using SLI/SLO metrics
• Knowledge of Linux network functions and SaaS/cloud-based environments
• Knowledge of AWS and GCP cloud platforms, including cloud networking concepts such as VPCs, security groups, transit gateways, and cloud-based load balancing
• Proven ability to mentor engineers, lead technical projects independently, and manage multiple initiatives in parallel, with demonstrated project management skills
• Excellent communication skills, both oral and written; ability to clearly represent technical domains and team outcomes to senior leadership and non-technical stakeholders
• Telecommunications technologies — VoIP, RTP, SIP peering/trunking, and SBC