Senior Infrastructure and Security Engineer
Many senior infrastructure roles eventually become dominated by support queues, routine administration and maintaining decisions made years earlier.
This opportunity is different.
The Australian Renewable Energy Agency is seeking a Senior Infrastructure & Security Engineer to strengthen its Microsoft cloud environment while contributing to a pipeline of uplift and project work.
This is a hands-on role spanning Microsoft cloud infrastructure, identity, endpoint management, automation and security controls.
The first year will lean more towards security uplift, remediation and improvement work than conventional infrastructure maintenance.
About ARENA
ARENA supports Australia's transition to net zero by funding renewable energy and decarbonisation projects, helping emerging technologies and commercial models move towards practical application.
The agency also shares knowledge from the initiatives it supports, helping government and industry make better future investment decisions.
With approximately 150 employees across Sydney, Canberra and Melbourne, ARENA undertakes nationally significant work while remaining small enough for individual engineers to have visibility and influence.
Secure and reliable technology enables its people to assess opportunities, manage investments and focus on higher-value work.
The Opportunity
Reporting to the Director, Security & Service Operations, you will improve ARENA's Microsoft cloud infrastructure and security environment.
The essential technology is in place, but some functionality remains underused, access models require further development, documentation can improve and several controls need review.




ARENA needs permanent expertise to assess the environment, define the required future state and turn priorities into delivery.
Your remit will include:
Entra ID, Conditional Access, identity governance and privileged access
Role-based access and user-lifecycle automation
Intune, endpoint management and device compliance
Defender, Purview, Netskope, DLP and information protection
Microsoft 365 and cloud configuration
PowerShell automation
Vulnerability and remediation coordination
Essential Eight and PSPF-aligned control uplift
Copilot and Microsoft AI readiness
Documentation and runbooks
The goal is to create a more secure and manageable environment with less manual administration.
Why This Role Is Different
Their vendor provides much of the routine monitoring, patching, backups, networking and support. ARENA retains ownership of direction, projects, change, security priorities and outcomes.
You will work with that vendor to plan changes, resolve escalations and deliver improvements. Depending on the initiative, you may complete the work directly or define the requirement and assure the provider's delivery.
This allows you to remain hands-on while focusing on higher-value improvement rather than routine support.




You will also join while ARENA is reviewing its environment and defining the next stage of its Microsoft cloud and security roadmap, giving you influence over the priorities and standards that follow.
About You
You may currently be a Senior Infrastructure Engineer, Senior Systems Engineer, Microsoft Cloud Engineer, Modern Workplace Engineer, Infrastructure & Security Engineer, Microsoft 365 Engineer or Cloud & Security Engineer.
You may also be a senior endpoint or EUC engineer with robust Microsoft security exposure who is ready for more responsibility.
You will be able to assess an environment, recommend a course of action and take responsibility for delivery.
Strong PowerShell capability will be important, together with experience improving identity, endpoint and security controls.
You do not need to be a cyber-governance specialist, but you must understand how security requirements translate into configuration and operational practice.
Most importantly, you will be curious and proactive, investigating why something is not working and improving the underlying environment rather than applying another workaround.
Why Join ARENA?
This role offers hands-on influence that can be difficult to find in a larger enterprise.
You will guide providers, contribute to decisions across the Digital environment and see the effect of your work when an access process becomes simpler, a control is strengthened or a manual activity is automated.
For an engineer seeking more autonomy and meaningful project work, this is an prospect to improve an entire environment while contributing to an organisation with national purpose.
ARENA also invests in professional development and supports people who want to expand their skills.
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📌 Senior Infrastructure And Security Engineer (Sydney)
🏢 Xceltium
📍 Sydney