Permanent | Highly Secure Environment | NV1 (or ability to obtain) Our client is a major national provider supporting some of Australia's most security-conscious customers. They are seeking a Senior Security Systems Engineer to join a specialised team responsible for building, maintaining, and securing a protected ICT environment as it progresses through a formal accreditation program. This is a hands-on technical role suited to someone who enjoys end-to-end ownership of secure systems, working across Windows, Linux, virtualisation, automation, and SIEM/SOAR integrations. You will play a key part in preparing a classified environment for accreditation, enhancing security maturity, uplifting observability, and supporting threat-led operational improvements. Location: Melbourne Work Arrangements: Hybrid Working Salary: $160,000 plus super Interview dates: Ideally week commencing 5th of January What You'll Be Doing Work closely with operational, infrastructure and security engineering teams to deliver a secure, compliant ICT environment. Operate, maintain and harden Windows, Linux (RHEL/CentOS) and virtualisation platforms (VMware/Hyper-V). Administer Active Directory, Group Policy, identity federation and role-based access controls. Perform patching, vulnerability management, system hardening and remediation activities aligned to IRAP, ASD and vulnerability findings. Monitor and respond to system alerts, logs and performance issues, integrating with SIEM/SOC operations. Manage storage, backup solutions, encryption, data integrity and compliance requirements. Automate routine tasks using PowerShell, Bash or Python to reduce risk and improve efficiency. Support the full lifecycle of the environment, including decommissioning legacy apps and uplifting systems to accreditation requirements. Contribute to accreditation documentation such as SSPs, risk treatment plans and baseline configurations. Mentor junior team members and participate in on-call rotations for a highly technical environment. Engage with stakeholders across the business, supporting change, planned works, and continuous improvement initiatives. What You'll Bring Essential NV1 security clearance or the ability to obtain one quickly. Strong experience across Windows, Linux, system integration, and secure configuration. Solid understanding of cyber security principles and how to apply them across build, operations, and maintenance. Experience implementing and maintaining controls aligned to frameworks such as ISO 27001, NIST, IRAP, ISM or the Essential Eight. Desirable Exposure to Network Detection and Response platforms, SIEM/SOAR integration, sensors/agents, or security analytics tooling. Experience with Citrix or virtual desktop environments. Previous involvement in IRAP, DISP, ISM or other compliance/accreditation projects. If you are interested in this role please click Apply today or reach out to Sophie Garrison for more info: sgarrison@launchrecruitment.com.au