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 solid 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.

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

📌 IT Senior Security Engineer (North Sydney)
🏢 CNS Australia
📍 North Sydney