Senior Security Platform Engineer - SRE

Optus is an Australian telecommunications company, delivering more than 11 million services to our customers every day across mobile, broadband, and digital solutions. Join Optus as a Senior Security Platform Engineer - SRE and play a critical role in ensuring the reliability, availability, and performance of the security platforms that support Cyber Defence and Threat Detection operations. You will apply Site Reliability Engineering (SRE) principles across SIEM, EDR, Vulnerability Management, and Exposure Management platforms, driving platform reliability through observability, automation, incident management, Service Level Objectives (SLOs), and continuous operational improvement. This role is ideal for a highly technical engineer with a passion for automation, operational excellence, and everything-as-code practices. Working closely with security platform engineers and Cyber Defence teams, you will build scalable monitoring, alerting, and automation solutions that reduce operational toil, improve platform resilience, and ensure security services operate effectively at enterprise scale. What You’ll Do Drive platform reliability and performance by defining and monitoring SLOs, SLIs, error budgets, and platform health across core security platforms. Lead reliability improvements through proactive risk identification, observability, reliability reviews, and engineering enhancements to ensure resilient security operations. Build and manage observability solutions across security platforms, providing end-to-end visibility through monitoring, alerting, and data flow integrity tracking. Develop monitoring and alerting automation using observability-as-code principles, ensuring proactive issue detection, efficient incident response, and reliable platform operations. Lead security platform incident response and recovery, coordinating major incidents, stakeholder communications, and post-incident reviews to minimise service disruption and prevent recurrence. Drive operational excellence through runbooks, incident trend analysis, on-call maturity, alert optimisation, and planned change management to improve platform resilience and reduce operational toil. Own capacity planning and performance monitoring across security platforms, forecasting growth, managing utilisation, and ensuring proactive visibility of capacity risks. Drive platform performance optimisation by identifying bottlenecks, coordinating capacity expansion, and providing data-driven insights to support platform investment and scalability decisions. What makes you perfect for the role? Relevant degree in Computer Science, IT, Software Engineering (or equivalent experience) with 5+ years’ experience in SRE, DevOps, or Platform Engineering within large enterprise environments. Proven expertise in SRE practices, including SLOs, SLIs, error budgets, observability, incident management, and reliability engineering for complex platforms. Hands-on experience with automation and platform engineering, including Python scripting, Infrastructure as Code, CI/CD pipelines, and everything-as-code methodologies. Strong knowledge of cloud and observability technologies. Experience supporting enterprise security platforms and operations, like SIEM, EDR, Vulnerability Management, and security operations/SOC environments. Excellent collaboration and communication skills with a reliability-first mindset, driving automation, continuous improvement, operational excellence, and blameless incident culture. What’s in it for you? 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 is 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 [email protected] 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