This is a Senior Technical Specialist - Mobile Voice role with Optus based in Sydney, NSW, AU Optus Role Seniority - senior More about the Senior Technical Specialist - Mobile Voice role at Optus Optus is an Australian telecommunications company, delivering more than 11 million services to our customers every day across mobile, broadband and digital solutions. We’re looking for a Senior Technical Specialist – Mobile Voice based in Macquarie Park, Sydney to act as a subject matter expert within Mobile Core Integration and Maintenance Engineering (IME). You’ll lead the testing and integration of new software, hardware and services into the Optus network, and provide Tier 3 technical support across voice platforms. What You’ll Do Own integration and testing for mobile voice infrastructure including IMS, HSS/SDM, 5G Stand‑Alone Core, VoNR, Diameter Routing, STP, subscriber provisioning, mobile voice billing, and cloud technologies such as OpenShift and AWS. Deliver Tier 3 support (including rostered on‑call, after‑hours and weekend work) for performance, design, fault resolution and optimisation. Lead vendor engagement to resolve defects and ensure integration deliverables are met prior to deployment. Plan and execute production cutovers with minimal customer impact and seamless rollback where required. Champion automation and AI to compress testing windows and accelerate delivery of new products and services. Provide coaching and mentoring to junior engineers and Operations staff, and act as second‑in‑charge to the manager when required. What You Bring Extensive telecommunications experience across 4G/5G mobile technologies, IMS & SDM, VoIP, IP networking and cloud infrastructure. Practical expertise with Nokia MSS/MGW, Ericsson IMS/SDM/5GC, Oracle STP and Ericsson DRA/DSC, including upgrades, planning, execution and acceptance activities. Strong working knowledge of SIP, SS7, Sigtran and Diameter, including trace interpretation and use of protocol analysers. UNIX administration and scripting experience (Shell, Perl), and familiarity with Cisco and Juniper networking platforms. Strong background in Tier 2/3 technical analysis and customer issue resolution, ensuring rapid restoration and optimal service performance. Clear communication skills, able to collaborate across Product, Architecture, IT, Billing, Operations and senior leadership. The good stuff…. Competitive remuneration and employee discounts. Make life easier (and more affordable) with $80 monthly credit and 25% off Optus products and unique shopping discounts with our retail partners. Flexible working arrangements with opportunities to work three days in the office, two days remote or home. Vibrant and collaborative office campus that includes cafes, convenience store, chill out zones, GP, post office, gym and on-site childcare centre. Competitive leave policies, including additional 'Connected’ days to focus on culture, family, health, community, or whatever’s important to you. We support growing families with inclusive, carer-neutral paid Parental Leave of up to 16 weeks. Direct your own development and build future-ready skills with Optus U’s industry-focused micro-credentials, developed with La Trobe and Macquarie Universities. Build meaningful connections through employee-led networks and diversity initiatives including Culture Connect, Elevate Women, Disability Network and Express Yourself (LGBTQIA). Put your wellbeing first with free access to counselling and support services, 24/7 — in-person, by phone, SMS, or video. Free Optus bus from Macquarie University Metro Station (every 6-8 minutes); morning and afternoon. 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 AccessibleRecruitment@optus.com.au or call 1800 309 170. For more information on Diversity, Inclusion & Belonging at Optus, please visit https://www.optus.com.au/about/inclusion-diversity Before we jump into the responsibilities of the role. No matter what you come in knowing, you’ll be learning new things all the time and the Optus team will be there to support your growth. Please consider applying even if you don't meet 100% of what’s outlined Key Responsibilities Owning integration and testing ️ Delivering Tier 3 support Planning production cutovers Key Strengths Telecommunications experience Technical analysis Scripting and UNIX administration Vendor engagement Automation and AI Coaching and mentoring A Final Note: This is a role with Optus not with Hatch.