Sr Security Engineer, Region Services

G'day! You've found an opportunity that could define your next chapter. Applicants must be Australian citizens and hold or be eligible to obtain an Australian Government Security Clearance with the ability to successfully complete an Organisational Suitability Assessment. More information regarding security clearances can be found at https://www.agsva.gov.au/. The Mission - Why This Programme, Why Now? You're joining at the defining moment of one of the most significant technology programmes Australia has ever undertaken. This programme will build and operate the dedicated cloud giving Australia's national security community and its allies the capability to see more, share more, innovate and act faster than ever before. The architectural decisions being made now - how we structure networking, implement security controls, and automate at scale - will shape how Australia's national security community operates for the next decade. You won't be inheriting someone else's design choices. You'll be making them. Your Role — The Security Engineering Lead Imagine being the person who defines how security is woven into the fabric of an entire portfolio of services — not as an afterthought, but as a foundational principle. As our Senior Security Engineer, you'll be the driving force behind a new era of distributed security ownership, building a model where security isn't siloed but embedded in the DNA of every builder team. You'll own threat modelling across critical services, lead the resolution of complex security challenges, and architect application security outcomes from secure design through code review. But this role goes beyond technical mastery — you'll be the Developer Advocate for Security, establishing and leading the Security Guardians programme that trains, mentors, and empowers security champions across systems engineering teams. This is your chance to scale your expertise across an entire organisation. Every security decision you make, every guardian you develop, every runbook you create will ripple outward — accelerating security reviews, reducing resolution timelines, and raising the bar on what secure-by-design truly means at national scale. You'll influence security strategy across partner organisations, communicate risk to senior leadership, and help builder teams navigate the intersection of speed and security with pragmatic, mission-focused guidance. You'll also be at the forefront of accelerating Generative AI proficiency across engineering teams — shaping how the next generation of builders thinks about security in an AI-augmented world. Key job responsibilities You'll be the architect of security outcomes across a portfolio of services that directly underpin Australia's national security capability. Your days will be defined by impact, not bureaucracy. You'll own threat modelling using structured methodologies like STRIDE and CAPEC, translating complex threat landscapes into pragmatic mitigation strategies that empower teams to build securely and ship confidently. You'll establish and lead the Security Guardians programme — identifying, training, and mentoring security ambassadors embedded within builder teams, creating a multiplier effect that scales security knowledge far beyond what any single engineer could achieve alone. When complex security challenges arise, you'll be the one teams turn to. You'll drive outcomes end-to-end — from design reviews and security assessments through penetration testing coordination and remediation tracking. You'll review code, scripts, and detection mechanisms, innovating on resolutions that others can learn from and replicate. You'll construct security and system runbooks for new problem domains, transforming your expertise into repeatable, scalable frameworks. You'll influence security strategy across related teams and partner organisations, ensuring consistency and raising the collective bar. You'll mentor system engineers and builders, growing their ability to