Mobile Core Network Engineer

The Role

We're looking for a Mobile Core Network Engineer to join the team responsible for Telnyx's global mobile core network. You'll own the infrastructure that powers our wireless platform - keeping it reliable, scalable, and ready for what comes next. This is a hands-on role spanning network operations, deployment automation, and incident response.

What You'll Do

Network Operations & Infrastructure

• Deliver and maintain core network services across global datacenters - ensuring high availability of PGWs, DRAs, GTP proxies, HSS, and STPs

• Design redundancy patterns (failover, active-active, disaster recovery) and drive service localisation in new regions

• Manage the GTP proxy fleet and DRA infrastructure: routing rules, IMSI translation, realm routing, and peer management

• Monitor traffic growth, forecast demand, and scale infrastructure ahead of need

Automation & Deployment

• Build and maintain Ansible playbooks and CI/CD pipelines for consistent, repeatable infrastructure changes

• Operate and evolve the signalling plane - Diameter, GTP-C/U, SS7 MAP - across roaming partner interconnects

• Design and maintain network connectivity: GRX/IPX peering, inter-datacenter tunnels, SCTP multihoming, and firewall rules

Observability & On-Call

• Build dashboards and alerting to catch issues before they become incidents

• Participate in on-call rotation for wireless infrastructure incidents

What We're Looking For

• Solid understanding of 3GPP EPC architecture: PGW, SGW, HSS, DRA, PCRF, STP, and their interfaces (S6a, S8, S5, Gx, S1-MME)

• Experience operating and troubleshooting mobile core network elements in production

• Strong networking fundamentals: IP routing, BGP/OSPF, VLANs, GRE/IPsec, SCTP, and packet-level troubleshooting (tcpdump/tshark)

• Strong Linux skills: systemd, network configuration, performance tuning, and scripting

• Hands-on experience with infrastructure automation - Ansible, Terraform, or equivalent

• Familiarity with containerised environments (Docker, Kubernetes) and CI/CD pipelines

• Experience with monitoring stacks: Prometheus, Grafana, Alertmanager

• Experience with AWS or similar cloud infrastructure

Nice to Have

• Experience with Diameter Routing Agents (freeDiameter or commercial DRAs) or GTP proxy platforms

• Knowledge of multi-IMSI SIM architectures, VoLTE/IMS, or roaming models (S8HR, LBO)

• Familiarity with IPX/GRX peering, GSMA roaming standards (IR.34), or network automation tooling (Netbox, NAPALM)

• Experience with Elixir, Go, or Python in a network infrastructure context