Join our Downer Professional Services team and play a key role in delivering complex defence and national security projects that safeguard Australia’s future.

Downer Professional Services comprises of three business units our Technical, Advisory, and Capability consulting practice, and Team Downer, which partners with CASG and NSSG as a major service provider to Defence. Together, we are a multi-disciplinary advisory and delivery partner of choice for clients across Defence and National Security.

We currently have an opportunity for a Cyber Security Engineer in Melbourne to execute security accreditation, assurance, and compliance activities in support of CA33 – Command Support Systems. The primary focus of this role is to maintain and support the security of CA33 capabilities throughout their lifecycle, ensuring compliance with Australian Government and Defence cyber security requirements.

What You’ll Do

This role offers a broad scope, with key role responsibilities including:

- Execute and coordinate security accreditation activities for CA33 Command Support Systems.
- Develop, maintain, and update security accreditation artefacts and supporting documentation.
- Conduct security risk assessments and document identified risks, treatments, and residual risk outcomes.
- Prepare security assurance evidence and documentation to support accreditation and ATO outcomes.
- Liaise with DCIAB and relevant stakeholders to support accreditation and assurance activities.
- Review security-related changes and provide advice regarding impacts to accreditation status and security posture.
- Provide cyber security advice, recommendations, and guidance to engineering and technical personnel as required.

What You’ll Bring

- Experience undertaking security accreditation, cyber security assurance,



or system authorisation activities within Defence or Government environments.
- Experience conducting cyber security risk assessments and supporting ATO processes.
- Working knowledge of the ISM and Defence cyber security requirements.
- Experience producing security accreditation documentation, risk assessments, and assurance reports.
- Strong written and verbal communication skills.
- Understanding of systems engineering principles and the SDLC.
- Familiarity with Defence ICT environments, command support systems, or mission systems.
- Knowledge of vulnerability management, system hardening, and security control implementation.

Due to the nature of the work, you are required to currently hold and maintain an AGSVA Security clearance as required by the Commonwealth. In some instances, compliance with International Traffic in Arms Regulations (ITAR) requirements may also be an inherent requirement.

More than anything, you’ll bring a strong work ethic, a positive attitude, and a commitment to delivering high-quality outcomes for our clients.

Why Downer Professional Services

At Downer Professional Services, we’re not just a workplace - we’re a business dedicated to contributing to the shaping of the future of defence in Australia. As the country’s only sovereign prime, we’re committed to making a real difference in protecting Australia’s interests.

What is means to belong at Downer Professional Services

- Meaningful work:



Help to deliver critical Defence projects that protect Australia and shape its future.
- Professional development: Access career mapping, accelerated learning programs, and shared learning through our Communities of Practice.
- Great perks: Enjoy discounts on healthcare, retail, vehicles, and more through Perks@Downer.
- Veteran support: Benefit from initiatives like up to 20 days of Reservist Leave to stay connected post-service.

You want your work to matter and so do we. With over 26,000 people across Australia, New Zealand and the Pacific, our team is made up of individuals with unique perspectives, backgrounds, and ideas.

We know that diversity makes us stronger and we actively celebrate it through our commitment to inclusion and belonging.

We’re committed to building a team that reflects the diverse communities we serve and we welcome people of all ages, genders, sexual orientations, cultures, abilities, and lived experiences. We especially encourage applications from those whose voices have traditionally been underrepresented in our industry, including women, Aboriginal and Torres Strait Islander Peoples, Māori and Pasifika Peoples, veterans, people with disability, and neurodivergent individuals. Even if your experience doesn’t align perfectly with this role, we’d still like to hear from you. If it feels like the right fit, apply - potential counts, and so do you.

As a WORK180 Endorsed Employer, we support flexibility that works for your life, inclusive leadership that values your voice, and equitable access to prospect so you can do your best work and bring your whole self to it.

If you need support or adjustments through the recruitment process, just let us know, we’re here to help you put your best foot forward.

📌 Cyber Security Engineer/Technical Professional (Melbourne)
🏢 Downer
📍 Melbourne