IT Senior Security Engineer

Salary: $150,000 – $160,000 per year

Why This Role Exists

Clients need security designs they can trust, and an engineer who stays accountable for them.

As a Senior Security Engineer, you design and implement security solutions for client engagements. You work from the first requirements workshop through to a defended, documented and handed-over environment.

You own the security outcome of your engagements. You stay accountable for the live design meeting client requirements, compliance obligations and applicable security frameworks.

This role suits someone whose authority comes from the quality of their security design, the evidence that it aligns with recognised compliance frameworks, and the trust clients place in it.

CNS trusts senior engineers with its highest-risk security engagements and with shaping how the Security practice delivers.

About CNS

CNS is a Managed Service Provider that has been in the market since 1988. We deliver Cloud, Network and Cyber Security solutions to organisations in Australia and overseas.

As a Microsoft Solutions Partner and ISO 27001 certified organisation, CNS already has a strong toolset, process framework, and client and partner relationships in place.

We employ more than 80 people globally. Our Professional Services practice designs and delivers security projects for our clients. We are hiring a Senior Security Engineer to lead that work.

Position Overview

Location: North Sydney, NSW

Employment Type: Full time

Hours: 8:00 AM to 5:00 PM

Reporting To : Head of Professional Services

Direct Reports: None. You will review and mentor the work of other resources.

Work Arrangement

CNS has an in-office first culture. You work from the office full time during onboarding. Once settled, one day per week working from home is encouraged. An ad hoc flexibility process covers additional arrangements.

After-Hours Availability

Availability outside core hours is part of the role during critical go-live events and major incidents. Advance scheduling and compensatory time apply per CNS policy.

Your Mission

Own the security design and delivery of your client engagements by:

- Designing defensive security architecture, with decisions and trade-offs recorded.

- Implementing security controls across identity, endpoint, cloud and network.

- Leading the security workstream through to a documented handover to Operations.

- Reviewing the security designs of other resources and holding the quality bar.

- Acting as the trusted security contact for your clients.

What You'll Be Doing

Security Architecture and Design Assurance

Design defensive security architecture for client engagements. Maintain reusable reference architectures and baselines so design is consistent across clients. Review designs from other resources before build and give clear approval or required changes. Run threat modelling for high-risk designs and make sure each attack path has a control and a detection.

Security Implementation and Delivery

Implement security controls across identity, endpoint, cloud and network that pass peer review first time. Lead the security workstream on client engagements. Hand over to Operations only when documentation and runbooks are complete. Own the security risk register and flag at-risk items to the Head of Professional Services within 24 hours. Approve security-impacting change records, with tested rollback plans.

Security Assessment and Advisory

Run security reviews and posture assessments of client environments. Present prioritised, costed recommendations. Shape security roadmaps and maturity uplift plans that clients can fund and sequence. Improve detection coverage by designing logging, tuning analytics and mapping coverage to attacker techniques. Turn threat intelligence and vendor changes into action for clients and the team.

Incident Support and Resilience

Act as an escalation point for Operations on security incidents, with containment advice and written root cause analysis. Turn incident findings into design, detection or hardening improvements. Build incident response playbooks and run tabletop exercises with clients.

Client Trust and Commercial Contribution

Set and reset expectations early when scope or risk changes. Help pre-sales by scoping security work, checking statements of work and flagging delivery risk before commercial sign-off. Raise scope variations as approved, billable changes in PSA before work starts. Keep timesheets accurate and billable hours on target.

Documentation and Knowledge

Deliver design documents, implementation records, runbooks and closure reports to CNS standards. Keep architecture diagrams and baselines current for each client environment. Publish knowledge base articles that cut resolution time for the wider team.

Team Capability and Practice Uplift

Mentor other resources through design reviews, structured guidance and direct knowledge transfer. Lead peer review of high-risk security changes. Build automation and process improvements that raise delivery quality. Model CNS security policy and ISO 27001 practice in daily work.

This Role Is For You If...

You will thrive in this role if you:

• Have 5+ years in a security engineering or security consulting role, with evidence across engagements.

• Hold a diploma or degree in IT, cyber security or a related field, or have senior-level industry certifications that show the same level of knowledge.

• Have worked in an MSP, consulting or multi-client environment.

• Have designed and implemented security solutions across Microsoft 365, Azure and network security platforms.

• Have advanced hands-on skills in the Microsoft security platform: Entra ID, Conditional Access, Privileged Identity Management, Defender for Endpoint, Defender for Cloud, Intune, Sentinel, Defender XDR and KQL.

• Have working capability in Fortinet and Palo Alto firewalls, Tenable, Microsoft Purview, PowerShell, Bicep and Azure DevOps.

• Know Zero Trust architecture, threat modelling and MITRE ATT&CK coverage mapping.

• Can map controls and evidence to ISO/IEC 27001, NIST CSF, the ACSC Essential Eight and the Australian Government ISM.

• Write design documents and delivery artefacts that clients accept with minimal rework.

• Have mentored other engineers and raised the quality of their output.

• Communicate openly and honestly with stakeholders at all levels, including when the message is uncomfortable.

• Take full ownership of outcomes and see work through until the result is right.

• Use AI tools well to solve new problems, check the output, and share useful workflows with the team.

• Hold, or are willing to obtain, at least four of these certifications: SC-200, SC-300, SC-401, SC-100, Fortinet Certified Solution Specialist - Network Security, PCNSE and CISSP.

Why Join CNS

Own the security outcome on your engagements.

Work on the highest-risk security engagements in the business.

Shape how the Security practice delivers.

Build on a strong toolset, process framework and set of client relationships.

Work in a team where teamwork is our superpower.

Get dedicated study time and full cost coverage for training and certifications.

Find opportunity beyond this role. Where you go from here comes down to the trust you build through your work.

Benefits

Rewards and recognition: peer-nominated and performance-based awards, paid as you accomplish them

Annual wellbeing allowance for health, fitness or personal well-being

Salary sacrifice, including novated lease and individual item options

Paid training and certifications, with dedicated study time

One work-from-home day each week after onboarding

Our Values

Be a Visionary: Innovation drives everything we do.

Be a Legend: Deliver exceptional customer outcomes.

Be a Teammate : Collaboration is our superpower.

Be Your Best : Pursue excellence every day.

Be Positive: Attitude shapes success.

Ready to Own the Security Outcome?

If you design security that clients trust and you want to lift the engineers around you, we want to hear from you.

Join CNS and help shape how our Security practice delivers.

Your application will include the following questions:

Which of the following statements best describes your right to work in Australia?

What's your expected annual base salary?

How many years' experience do you have in a security engineering or security consulting role?

How much notice are you required to give your current employer?

Which of the following certifications do you hold (SC-200, SC-300, SC-401, SC-100, Fortinet, PCNSE, CISSP)?

How many years of hands-on experience do you have with Microsoft Sentinel and Defender XDR?