Core Network Maintenance Engineer

About the role

This role covers 7x24 on-call support and hands-on operations of Huawei core network nodes (MME, SGW, PGW, AMF, SMF, UDM, AUSF, IMS, PCRF) for an operator. It includes fault isolation, preventive maintenance, change management, incident handling and reporting, as well as mentoring junior engineers.

Key responsibilities

• Provide 7x24 on-call support, monitor alarms, isolate faults and lead service recovery within SLA.
• Perform preventive maintenance: health checks, log collection, KPI analysis, capacity audit and risk assessment, and submit inspection reports.
• Execute core network changes: configuration updates, patches, software upgrades, data migration, new features and cutover, including plans and rollback procedures.
• Carry out signaling traces, call flow analysis and root cause analysis, and close incidents with reports.
• Communicate with the operator customer on incident status, maintenance schedules and risks, and submit weekly and monthly maintenance reports.
• Maintain technical documents, network topology, procedures and the knowledge base, and coach junior engineers.
• Support project delivery, expansion, new site integration and roaming interconnection on the core network side.
• Follow the shift roster and attend emergency outage repairs at night and on weekends.

Required profile

• Bachelor's degree in Telecommunications, Electronic Engineering, Computer Science or a related field.
• At least 2 years of experience in telecom core network O&M for an operator or vendor; hands-on Huawei EPC / 5G Core / IMS experience preferred.
• Familiarity with telecom SLA, change control and incident classification; able to work under pressure during major outages.
• Full availability to work; good English for technical reading, writing and speaking; Portuguese is a strong plus.
• Huawei HCIA / HCIP Core Network certification preferred.

Required skills

• Solid knowledge of 4G EPC and 5G SA architecture, S1AP, GTP, Diameter, SBI interfaces and VoLTE/VoNR procedures; skilled in signaling trace.
• Basic Linux commands and database knowledge.
• Familiarity with Huawei U2000 / eSight NMS.
• Good customer communication and documentation skills.