Senior Technical Specialist

Singapore Telecommunications; Sydney; On-site; AUD 140,000 - 200,000; Full time

Benefits offered by this job

Competitive remuneration

Optus staff discounts

On-site facilities

Job summary

Singapore Telecommunications is seeking a Voice and Data Core Senior Technical Specialist to ensure the performance and reliability of critical network services. The role provides 24/7 on-site support in Macquarie Park, Sydney, with rotating day, afternoon and night shifts and technical leadership across the Core networks.

You will diagnose faults, lead incident escalations, perform root cause analyses, and mentor the team to drive operational excellence while collaborating with vendors and

Qualifications

• Deep technical expertise in Mobile Packet and Policy Control (4G/5G).
• Experience in service operations, hands-on network support and troubleshooting.
• Ability to lead technical escalations and drive improvements with vendors.
• Strong governance and collaboration with cross-functional teams.

Responsibilities

• Provide 24/7 operational support for Voice and Data Core platforms.
• Lead major incident escalations and coordinate cross-functional teams.
• Perform root cause analysis and drive permanent corrective actions.
• Support EPC, 5G Core, IMS and Subscriber Data platforms operations.
• Troubleshoot mobility, data services and SIP/Diameter/SIGTRAN issues.
• Monitor performance, drive reliability, and participate in CAB processes.
• Mentor team members and promote best practices in operations.

Skills

Mobile Packet Core

Policy Control

4G/5G Core

CCS7

Diameter

HTTP/2

SIGTRAN

Vendor governance

Incident management

Technical leadership

Tools

Ericsson Nodes

Job description

Singapore Telecommunications – Macquarie Park NSW

We don’t sit back and wait for the future to happen, we are out there crafting our own path through new technology, innovation, and investment. We are truly a challenger brand, with challenger spirit.

We don’t sit back and wait for the future to happen, we are out there crafting our own path through new technology, innovation, and investment. We are truly a challenger brand, with challenger spirit.

About the Role

The Voice and Data Core Senior Technical Specialist is responsible for ensuring the performance, availability, and reliability of critical network services within the Tier 2 Network Operations team. The role provides 24/7 operational support across Voice and Data Core platforms, managing incidents, problems, and changes while working closely with vendors and engineering teams to support network enhancements and service improvements.

This position also provides technical leadership, contributes to the delivery of new network capabilities, and mentors team members to drive operational excellence.

Location: Macquarie Park, Sydney (100% onsite)

Work Pattern: 24/7 rotating shift roster, including day, afternoon, and night shifts

What You'll Do

• Diagnose and resolve complex faults impacting Packet Core, IMS, Subscriber Data Management and 5G Core services escalated from Tier 1.
• Lead technical escalations during major incidents, coordinating cross-functional teams to restore services and minimise customer impact.
• Perform detailed root cause investigations and drive permanent corrective actions through structured problem management practices.
• Support and maintain operational performance across EPC, 5G Standalone Core, IMS and Subscriber Data Management platforms.
• Troubleshoot customer-affecting issues relating to mobility, data services, subscriber authentication, policy control, VoLTE and VoWiFi services.
• Analyse signalling and service flows across SIP, Diameter, HTTP/2, REST APIs, SS7 and SIGTRAN protocols.
• Collaborate with Engineering and Vendors to support software upgrades, capacity expansions, technology refreshes and strategic network initiatives.
• Monitor service performance and key operational metrics, identifying opportunities to improve network reliability, customer experience and operational efficiency.
• Represent Operations within Change Advisory Board (CAB) processes and ensure deployment activities meet operational readiness and quality standards.
• Drive continuous improvement initiatives across event management, alarming, automation and operational tooling.
• Support the introduction of new technologies and ensure operational preparedness for future network capabilities.
• Mentor and coach team members, promoting technical excellence, knowledge sharing and operational best practice.

What You'll Bring

• Deep technical expertise in Mobile Packet and Policy Control (4G and 5G), with deep knowledge of CCS7, diameter, HTTP/2, and SIGTRAN signalling standards.
• Demonstrable experience in service operations within telecommunications, including hands-on network support and troubleshooting preferably on Ericsson Nodes including EPG, MME, WMG, PCC, PCG, CCDM, CCSM, SBG, MTAS, CSCF, HSS, HLR, DRA etc.
• Demonstrated ability to effectively manage technology vendors and maintain strong governance practices.
• Confident in communicating technical concepts, presenting recommendations, and responding effectively to management feedback.
• Proactive problem-solver who takes ownership of issues, investigates root causes, and drives practical, timely solutions.
• Recognised Subject Matter Expert with strong partner engagement skills and a collaborative, relationship‑building approach.

The good stuff…

• Competitive remuneration, plus $80 monthly credit, 25% off Optus products and exclusive shopping discounts with our retail partners — making everyday life a little more affordable.
• An office campus that has it all - cafes, chill-out zones, GP, post office, gym, and on-site childcare centre. It’s built for real life.

• Great leave policies, including additional 'Connected’ days to focus on culture, family, health, community, or whatever matters most to you.
• Inclusive, carer-neutral paid Parental Leave of up to 16 weeks, because family comes first.
• Build meaningful connections through colleague-led networks and diversity initiatives including Culture Connect, Elevate Women, Disability Network, and Express Yourself (LGBTQIA+).
• Your wellbeing matters, so we offer free counselling and support services, available 24/7 in-person, by phone, SMS, or video.
• A free Optus bus from Macquarie University Metro Station (every 6-8 minutes); morning and afternoon. Or, heaps of onsite parking. Plus, end-of-trip facilities with lockers, showers, irons, and hair dryers.

At Optus, we are strengthened by others and that means valuing diversity and saying ‘yes’ to embracing individual differences. We are committed to ensuring that our application process provides an equal employment opportunity to all job seekers, including individuals from diverse gender, cultural and linguistic backgrounds, individuals with a disability, individuals identifying as being part of the LGBTQIA+ community, individuals who may have served in the armed forces or who identify as Aboriginal and/or Torres Strait Islander. We also want to do our best to make our recruitment process inclusive. If you require any adjustments or accessibility support to participate fairly and equitably in the recruitment process, please email ***************@optus.com.au or call 1800 309 ***.

For more information on Diversity, Inclusion & Belonging at Optus, please visit https://www.optus.com.au/about/inclusion-diversity

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