Security Platform Engineer - Microsegmentation

Optus is an Australian telecommunications company, delivering more than 11 million services to our customers every day across mobile, broadband and digital solutions. As a Security Platform Engineer – Microsegmentation , you will be responsible for designing, implementing, and continuously enhancing Optus' enterprise microsegmentation capability to strengthen network security and reduce the risk of lateral movement by attackers. Working within the Cybersecurity Platform Engineering team, you will map application communication flows, develop and enforce segmentation policies, and integrate the microsegmentation platform with the broader security ecosystem to improve visibility, control, and protection across the enterprise environment. This is a hands-on engineering role focused on building a new security capability from the ground up. You will collaborate closely with Cybersecurity, Network Engineering, and Telco Network Engineering teams to ensure segmentation strategies are aligned across both enterprise and telecommunications networks. In addition to platform engineering, you will establish operational processes, automation, playbooks, and best practices that enable the platform to scale effectively, making it an ideal opportunity for someone who enjoys creating and evolving security solutions rather than simply maintaining existing systems. WHAT YOU'LL DO Cybersecurity Platform Engineering and Operationalisation Build, configure, and operate the enterprise microsegmentation platform, delivering effective segmentation controls across the environment. Analyse application communication flows and define, implement, and maintain least-privilege segmentation policies for critical workloads and high-value assets. Integrate segmentation telemetry with SIEM platforms to enhance visibility of policy violations, suspicious activity, and lateral movement risks. Cross-Platform Segmentation Alignment and Governance Partner with Telco Network Engineering and Security Architecture teams to align enterprise microsegmentation with network-layer segmentation and Zero Trust strategies. Develop segmentation architecture models, identify control gaps and dependencies, and provide technical expertise to cross-functional governance forums. Active Defence Integration and Platform Operations Maintain platform health, upgrades, policy enforcement, and integrations with SIEM and network security tools to ensure consistent security controls and visibility. Develop operational documentation and standards, monitor segmentation coverage, identify gaps, and support incident response through policy analysis and containment activities. Automation and Engineering Improvement Develop automation for application flow mapping, policy creation, and validation, improving efficiency and consistency across the microsegmentation platform. Build and maintain CI/CD pipelines for policy deployment and contribute reusable tooling and automation capabilities across the Network Security Platform Engineering team. WHAT WE'RE LOOKING FOR Relevant tertiary qualification in Computer Science, IT, Network Engineering, Cybersecurity, or equivalent practical experience. 5+ years hands-on experience in network security, workload security, or platform engineering with exposure to network segmentation concepts. Hands-on experience with enterprise microsegmentation platforms (Illumio, Guardicore, Cisco Secure Workload, ColorTokens Xshield, or similar) in large-scale production environments. Strong knowledge of network security, segmentation, and Zero Trust principles, including workload isolation, least-privilege access, and enterprise networking fundamentals. Proven ability to analyse application and network traffic flows, troubleshoot policy issues, and create clear technical documentation, standards, and runbooks. Experience with SIEM integrations, telemetry pipelines, scripting (Python/Bash), and CI/CD or configuration-as-code practices. Exposure to network device segmentation technologies (Cisco TrustSec, Juniper, Palo Alto) within telecommunications, critical infrastructure, or financial services environments. Builds strong stakeholder relationships, works effectively across teams, and takes ownership of delivering reliable security outcomes. Applies a careful, risk-aware approach to segmentation while leveraging automation to improve efficiency and support scalable capability growth. WHAT'S IN IT FOR YOU Competitive remuneration with $80 monthly credit and 25% off Optus products, plus retail partner discounts Flexible working: three days in office, two days remote Competitive leave policies including additional 'Connected' days for culture, family, health, or community Inclusive, carer-neutral paid Parental Leave of up to 16 weeks Self-directed development through Optus U micro-credentials with La Trobe and Macquarie Universities Employee-led networks including Culture Connect, Elevate Women, Disability Network, and Express Yourself (LGBTQIA+) Free 24/7 counselling and wellbeing support in-person, phone, SMS, or video 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 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