Job Description

Optus is a leading telecommunications and technology company, delivering innovative solutions that keep millions of Australians connected. As we continue to evolve into a digital-first, AI-enabled organisation, our Cyber Defence Operations team plays a critical role in protecting our customers, networks and data.

We’re looking for a Threat Detection Engineer to join our Cyber Defence Operations – Defence Operations team, where you will design, build and continuously improve detection capabilities to defend against evolving cyber threats.

Due to the nature of this role and the environments supported, Australian Citizenship, and the ability and willingness to obtain and maintain a Government Security Clearance is required.

What You’ll Do

Partnering closely with Cyber Security leaders, SOC analysts, threat intelligence, and engineering teams, you will:

• Design, develop and optimise detection logic across SIEM and EDR platforms (e.g. Microsoft Sentinel, Defender XDR, Cortex XSIAM)
• Own the end-to-end detection lifecycle including requirements gathering, rule authoring, testing, deployment, tuning, and retirement
• Improve detection precision through noise reduction, alert tuning, suppression logic and false positive management
• Configure analyst-facing environments including incident views, triage workflows, alert grouping and scoring models
• Conduct detection coverage analysis aligned to MITRE ATT&CK and threat intelligence insights
• Collaborate with SOC, threat hunting and red/purple teams to continuously uplift detection capability and operational effectiveness
• Contribute to detection-as-code practices, including version control, documentation, and CI/CD pipelines
• Participate in security operations rotations, supporting incident triage and response activities

What You’ll Bring

• Hands-on experience in cyber security operations (SOC, incident response or threat detection engineering) – this is essential
• Strong understanding of security concepts including attack lifecycle, threat actor techniques, and alert triage workflows
• Familiarity with SIEM and EDR platforms, and ability to analyse logs across endpoint, identity and network sources
• Experience or exposure to detection engineering, rule creation, or threat-informed defence practices
• Strong problem-solving skills with the ability to balance detection coverage and operational noise
• Effective communication skills and ability to document clearly in operational environments
• A growth mindset, with eagerness to learn and develop within a high-performing cyber team

The Good Stuff…

• Competitive remuneration and exclusive employee discounts
• Flexible working with a hybrid model (office and home)
• Access to on-site facilities including cafes, gym, childcare and more
• Inclusive parental leave and flexible policies supporting families
• Ongoing development through Optus U and industry-recognised learning programs
• Employee-led networks supporting diversity, inclusion and belonging
• 24/7 wellbeing and support services

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. We're here to help. When you contact us, please advise your preferred method of contact and we will be in touch within 48 hours.

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