Investigate end-to-end attachment failures across S6a (Diameter), MAP (SS7), GTP-C, and GTP-U
Decode pcap traces from DRA, STP, and GTP proxy capture points to isolate signalling failures
Trace individual IMSIs across protocols and partner networks to find where sessions break
Diagnose DNN/APN routing mismatches, IMSI-pinned APN gaps, and private wireless gateway configuration issues
Handle customer-reported SIM connectivity issues end-to-end — from initial report through root cause to fix
Manage and troubleshoot HSS/HLR, DRAs (freeDiameter with custom Python transforms), STPs, PGWs, SMFs, and GTP proxies (Go)
Work with etcd-based steering/blocking infrastructure (forbidden PLMNs, platform-level blocking, 3G blocking)
Operate the GTP proxy routing database (IMSI groups, IMSI-pinned APNs, cache invalidation)
Participate in vendor management — escalating and driving resolution with platform vendors and roaming partner NOCs
Support sponsored roaming relationships and direct bilateral agreements
Investigate roaming registration failures, NRTRDE gaps, and steering/blocking issues
Coordinate with partner NOCs on S6a/MAP/GTP incidents, including pcap exchange and joint root-cause analysis
Use and extend our pcap analysis tooling and protocol decoders to speed up investigations
Contribute configuration and automation for EPC infrastructure (Ansible, Kubernetes)
Improve observability — Grafana dashboards, alerting rules, protocol-level metrics
Where a fix or diagnostic needs a small code change, be comfortable making one — but this is an operations role, not a software-development one