Five9 is a leading provider of cloud software for the enterprise contact center market, bringing the power of the cloud to thousands of customers and facilitating more than three billion customer interactions annually. Since 2001, Five9 has led the cloud revolution in contact centers, helping organizations transition from legacy premise-based solutions to the cloud. Five9 provides businesses with cloud contact center software that is reliable, secure, compliant and scalable, which is designed to create exceptional customer experiences, increase agent productivity and deliver tangible business results.

To complement our rapid growth, we are actively sourcing for a Network Engineer to operate in a 24/7 Software-as-a-Service (SaaS) environment maintaining IP Networking components in a production setting.  In this role you will:

• Design, engineer, and oversee highly scalable CI/CD pipelines for automated testing, digital-twin dry-running, and zero-downtime deployment of configurations across massive physical and virtual network fabrics.
• Champion the "Network-as-Code" paradigm, establishing enterprise-wide GitOps workflows and enforcing source control (Git) as the absolute single source of truth for all network state, policy, and infrastructure design.
• Drive the strategic vision for network automation, designing complex, reusable code frameworks and Playbooks to permanently eliminate manual configuration and operational "toil" at a global scale.
• Design and optimize massive-scale software-defined networks (SDN) and container networking interfaces (CNIs) supporting ultra-high-throughput, multi-region cloud and bare-metal environments.
• Serve as the ultimate technical authority (SME / Tier 4) for complex network, routing, and overlay issues, rapidly deciphering and resolving the most difficult challenges across physical underlays and software-defined layers.
• Design and implement next-generation telemetry, monitoring, and alerting-as-code platforms, leveraging advanced heuristics for proactive auto-remediation of performance, security, and capacity issues.

Key Responsibilities:

• Partner at a strategic level with Enterprise Designers, SRE leaders, and Platform teams to build and implement highly resilient, secure, and multi-tenant-isolated network infrastructure.
• Establish coding standards and write/review sophisticated Infrastructure-as-Code (IaC) using Ansible, Terraform, Helm, Python, and Bash.
• Lead the engineering, deployment, and optimization of modern overlay and container networking solutions, particularly VXLAN, OVN (Open Virtual Network), and Project Calico.
• Design the automation of complex security and traffic management policies across enterprise-grade firewalls (Palo Alto/Fortinet) and load balancers (F5 BIG-IP/Cloudflare/Octavia).
• Embed "Security-as-Code" directly into CI/CD pipelines, engineering automated validation gates for security groups, ACLs, and firewall rules prior to production pushes.
• Engineer robust, automated network validation suites to continuously verify network health, state, and complex routing tables (BGP, OSPF) pre- and post-deployment.
• Drive the adoption of code-based infrastructure definitions and dynamic, living technical documentation (e.g., NetBox, Git Markdown), setting the standard for documentation across the engineering organization.

Requirements:

• 8+ years of progressive experience in Network Engineering, DevOps, or SRE roles, with a deeply established focus on large-scale network design, automation, and Infrastructure-as-Code (IaC).
• Expert-level proficiency in engineering complex network automation tooling utilizing Ansible, Terraform, and Python (including deep experience with network-specific libraries like Netmiko, Nornir, or NAPALM).
• Deep design and operational expertise with massive-scale software-defined networks (SDN) and overlays, specifically VXLAN, OVN, and Project Calico.
• Advanced mastery of Kubernetes networking designs (CNIs, Ingress controllers, Service Mesh, Kube-Proxy behaviors) at an enterprise scale.
• Extensive, expert-level experience engineering and automating enterprise edge, routing, and security fabrics, including Cisco Nexus (9k/7k/5k/2k), Arista, Versa SD-WAN, and firewalls (Palo Alto and Fortinet).
• Authoritative knowledge of API-driven application delivery and load balancing across monolithic and cloud-native stacks (e.g., F5 BIG-IP AS3, Cloudflare APIs, Octavia LBaaS).
• Deep Linux internals and networking expertise, including advanced knowledge of Linux network namespaces, virtual interfaces, eBPF/iptables, and kernel-level routing.
• CCIE-level (or equivalent) mastery of core routing protocols (BGP, OSPF, MPLS, EVPN) and a comprehensive understanding of how virtual/container overlay networks map to physical underlays.
• Extensive experience designing and scaling CI/CD platforms (e.g., GitLab CI, Jenkins, GitHub Actions) and implementing test-driven development (TDD) for infrastructure changes.
• Unparalleled troubleshooting capabilities utilizing advanced packet analysis (tcpdump/Wireshark), NetFlow, and log aggregation platforms to trace asymmetric routing and microburst traffic across hybrid fabrics.
• Proven track record of technical leadership, including mentoring mid-level engineers, leading design review boards, and driving cross-functional engineering initiatives.
• Deep telecommunications background—specifically VoIP, RTP, SIP peering/trunking, and Session Border Controllers (SBC)—is highly advantageous.
• Exceptional verbal and written communication skills, with the ability to translate complex technical concepts to executive stakeholders while fostering a collaborative, DevOps-oriented engineering culture.